Transparent conductive oxide having an embedded film

ABSTRACT

The present invention is directed to coated articles. A substrate is coated with an underlayer having at a first underlayer film made of a first high refractive index material. A transparent conductive oxide layer over at least a portion of the underlayer. An embedded film is embedded within the transparent conductive oxide layer wherein the embedded film comprises a second high refractive index material.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to coated articles having a low emissivity andneutral color.

Description of Related Art

Transparent conductive oxides (“TCOs”) are applied to the substrate toprovide the coated article with lower emissivity and lower sheetresistance. This makes TCOs particularly useful in electrodes (forexample solar cells) or heating layers, activing glazing units orscreens. TCOs are usually applied by vacuum deposition techniques, suchas magnetron sputtering vacuum deposition (“MSVD”). Generally a thickerTCO layer provides a lower sheet resistance. The thickness of the TCO,however, impacts the color of the coated article. Therefore, there is aneed to adjust the coloring effect caused by TCO layers. There is also aneed to minimize the thickness of a TCO layer so as to minimize theimpact the TCO has on the color of the coated article while stillmaintaining the required sheet resistance.

Coating stacks may corrode over time. To protect from this, protectiveovercoats can be applied to coatings. For example, titanium dioxidefilms disclosed in U.S. Pat. Nos. 4,716,086 and 4,786,563 are protectivefilms that provide chemical resistance to a coating. Silicon oxidedisclosed in Canadian Patent Number 2,156,571, aluminum oxide andsilicon nitride disclosed in U.S. Pat. Nos. 5,425,861; 5,344,718;5,376,455; 5,584,902 and 5,532,180; and in PCT International PatentPublication No. 95/29883 are also protective films that provide chemicalresistance to a coating. This technology could be advanced by morechemically and/or mechanically durable protective overcoats.

SUMMARY OF THE INVENTION

A coated article includes a substrate, an underlayer over the substrate.The underlayer includes a first layer. The first layer contains a highrefractive index material. A second layer is positioned over at least aportion of the first layer. The second layer contains a low refractiveindex material. A transparent conductive film positioned over at least aportion of the underlayer. The coated article has a sheet resistance ofat least 5Ω/□ and at most 25Ω/□. The coated article has a color with ana* of at least −9 and at most 1, a b* of at least −9 and at most 1.

Optionally, the coated article can have a protective layer over at leasta portion of the transparent conductive oxide layer. The protectivelayer includes a first protective film over at least a portion of thetransparent conductive oxide layer, and a second protective film over atleast a portion of the first protective film. The second protective filmis the outer-most film in the coating stack, and includes a mixture oftitania and alumina. Optionally, the protective layer can include athird protective film positioned between the first protective film and asecond protective film.

A method of forming a coated substrate includes providing a substrate. Atransparent conductive oxide is identified and a thickness for thetransparent conductive oxide is determined that will provide a sheetresistance of at least 5Ω/□ and at most 25Ω/□. An underlayer having afirst underlayer material and a second underlayer material isidentified. Thickness for the first underlayer and the second underlayerare determined that will provide the coated substrate with a colorhaving an a* of at least −9 and at most 1, a b* of at least −9 and atmost 1. The thicknesses of the two films in the underlayer are used totune the color of the coated substrate. Since the color is impacted bythe thickness of the transparent conductive oxide film, the color istuned after the thickness of the transparent conductive oxide film isdetermined. The first underlayer film including the first underlayermaterial is applied over at least a portion of the substrate at thefirst underlayer film thickness. A second underlayer film including thesecond underlayer material is applied over at least a portion of thefirst underlayer at the second underlayer thickness. A transparentconductive oxide layer having the transparent conductive oxide isapplied over at least a portion of the second underlayer film at thetransparent conductive oxide film thickness.

A coated article having a color with an a* of at least −9 and at most 1and a b* of at least −9 and at most 1 made by the following steps. Atransparent conductive oxide is identified and a thickness for thetransparent conductive oxide is determined that will provide a sheetresistance of at least 5Ω/□ and at most 25Ω/□. An underlayer having afirst underlayer material and a second underlayer material isidentified. Thickness for the first underlayer and the second underlayerare determined that will provide the coated substrate with a colorhaving an a* of at least −9 and at most 1, a b* of at least −9 and atmost 1. The thicknesses of the two films in the underlayer are used totune the color of the coated substrate. Since the color is impacted bythe thickness of the transparent conductive oxide film, the color istuned after the thickness of the transparent conductive oxide film isdetermined. The first underlayer film including the first underlayermaterial is applied over at least a portion of the substrate at thefirst underlayer film thickness. A second underlayer film including thesecond underlayer material is applied over at least a portion of thefirst underlayer at the second underlayer thickness. A transparentconductive oxide layer having the transparent conductive oxide isapplied over at least a portion of the second underlayer film at thetransparent conductive oxide film thickness.

A coated article including a substrate. An underlayer is positioned overat least a portion of the substrate. The underlayer includes at least afirst underlayer film over at least a portion of the substrate, and anoptional second underlayer film over at least a portion of the firstunderlayer film. The first underlayer film contains a first highrefractive index material. The optional second underlayer film containsa first low refractive index layer. A transparent conductive oxide layeris positioned over at least a portion of the first or optional secondunderlayer film. A second high refractive index material is embeddedwithin the transparent conductive oxide layer. The coated article has asheet resistances of at least 5Ω/□ and at most 25Ω/□. The sheetresistance is at least 35% higher than without the second highrefractive index material embedded within the transparent conductiveoxide layer.

Optionally, the coated article can have a protective layer over at leasta portion of the transparent conductive oxide layer. The protectivelayer includes a first protective film over at least a portion of thetransparent conductive oxide layer, and a second protective film over atleast a portion of the first protective film. The second protective filmis the outer-most film in the coating stack, and includes a mixture oftitania and alumina. Optionally, the protective layer can include athird protective film positioned between the first protective film and asecond protective film.

A coated article including a substrate. An underlayer is positioned overat least a portion of the substrate. The underlayer includes at least afirst underlayer film over at least a portion of the substrate, and anoptional second underlayer film over at least a portion of the firstunderlayer film. The first underlayer film contains a first highrefractive index material. The optional second underlayer film containsa first low refractive index layer. A first transparent conductive oxidelayer is positioned over at least a portion of the first or optionalsecond underlayer film. An embedded film is positioned over at least aportion of the first transparent conductive oxide layer. The embeddedfilm has a second high refractive index material. A second transparentconductive oxide layer is positioned over at least a portion of thesecond transparent conductive oxide layer. The coated article has asheet resistances of at least 5Ω/□ and at most 25Ω/□. The sheetresistance is at least 35% higher than without the embedded film.

Optionally, the coated article can have a protective layer over at leasta portion of the transparent conductive oxide layer. The protectivelayer includes a first protective film over at least a portion of thetransparent conductive oxide layer, and a second protective film over atleast a portion of the first protective film. The second protective filmis the outer-most film in the coating stack, and includes a mixture oftitania and alumina. Optionally, the protective layer can include athird protective film positioned between the first protective film and asecond protective film.

A method of forming a coated article; a method of increasing the sheetresistance; or a method of increasing the light transmission through acoated article. A substrate is provided. An underlayer is applied overat least a portion of the substrate. A first underlayer film is appliedover at least a portion of the substrate. The first underlayer film hasa first high refractive index material. An optional second underlayerfilm is applied over at least a portion of the first underlayer film.The optional second underlayer film has a first low refractive indexlayer. A first transparent conductive oxide layer is applied over atleast a portion of the first or optional second underlayer film. Anembedded film is applied over at least a portion of the firsttransparent conductive oxide film. The embedded film has a second highrefractive index material. A second transparent conductive oxide film isapplied over at least a portion of the embedded film. Optionally aprotective layer can be applied over the second transparent conductiveoxide film. The optional protective layer includes a first protectivefilm over at least a portion of the transparent conductive oxide layer,and a second protective film over at least a portion of the firstprotective film. The second protective film is the outer-most film inthe coating stack, and includes a mixture of titania and alumina.Optionally, the protective layer can include a third protective filmpositioned between the first protective film and a second protectivefilm.

A coated article made by the following steps. A substrate is provided.An underlayer is applied over at least a portion of the substrate. Afirst underlayer film is applied over at least a portion of thesubstrate. The first underlayer film has a first high refractive indexmaterial. An optional second underlayer film is applied over at least aportion of the first underlayer film. The optional second underlayerfilm has a first low refractive index layer. A first transparentconductive oxide layer is applied over at least a portion of the firstor optional second underlayer film. An embedded film is applied over atleast a portion of the first transparent conductive oxide film. Theembedded film has a second high refractive index material. A secondtransparent conductive oxide film is applied over at least a portion ofthe embedded film. Optionally a protective layer can be applied over thesecond transparent conductive oxide film. The optional protective layerincludes a first protective film over at least a portion of thetransparent conductive oxide layer, and a second protective film over atleast a portion of the first protective film. The second protective filmis the outer-most film in the coating stack, and includes a mixture oftitania and alumina. Optionally, the protective layer can include athird protective film positioned between the first protective film and asecond protective film.

A method of increasing the sheet resistance of a coated article. Acoated article is provided. The coated article has a substrate and atransparent conductive oxide layer over at least a portion of thesubstrate. The coated article is processed with a post-depositionprocess. The post deposition process can be tempering the coatedarticle, heating the entire coated article by placing it into a furnace,flash annealing only a surface of the transparent conductive oxide layeror passing an Eddy current through the transparent conductive oxidelayer. Alternatively, a coated article having a sheet resistance of lessthan 25 ohms per square made by the method described in this paragraph.

A method of increasing sheet resistance of a coated article. A substrateis provided. A transparent conductive oxide is applied over at least aportion of the substrate. A post-deposition process is applied to thesubstrate that is coated with the transparent conductive oxide. The postdeposition process can be tempering the coated article, heating theentire coated article by placing it into a furnace, flash annealing onlya surface of the transparent conductive oxide layer or passing an Eddycurrent through the transparent conductive oxide layer.

A coated article is a substrate having a coating stack. At least aportion of the substrate is coated with a functional coating. Aprotective layer is applied over at least a portion of the functionalcoating. The protective layer has a first protective film over at leasta portion of the functional coating, and a second protective film overat least a portion of the functional coating. The second protective filmis the last film within the coating stack, and includes titania andalumina. Optionally, a third protective film can be positioned betweenthe first protective film and the second protective film, or between thefirst protective film and the functional coating.

A method of making a coated article including providing a substrate. Afunctional coating is applied over at least a portion of the substrate.A first protective film is applied over at least a portion of thefunctional coating. A second protective film that includes titania andalumina is applied over at least a portion of the first protective film.Optionally, a third protective film is applied between the firstprotective film and the second protective film, or between the firstprotective film and the functional coating.

A method of reducing the absorption, resistance or emissivity of atransparent conductive oxide layer. A substrate is provided. Atransparent conductive oxide layer is applied over at least a portion ofthe substrate in an atmosphere that comprises between 0% and 2.0%oxygen.

A coated article having reduced absorption, resistance or emissivitycomprising a transparent conductive oxide layer made by the followingsteps. A substrate is provided. A transparent conductive oxide layer isapplied over at least a portion of the substrate in an atmosphere thatcomprises between 0% and 2.0% oxygen.

BRIEF DESCRIPTION OF THE DRAWING(S)

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

FIGS. 1a, 1b, 1c and 1d are side views (not to scale) of coatingsincorporating a feature of the invention;

FIGS. 2a, 2b, 2c, 2d and 2e are side views of other coatings (not toscale) incorporating a feature of the invention;

FIGS. 3a, 3b, 3c, 3d, 3e are side views of other coatings (not to scale)incorporating a feature of the invention;

FIGS. 4a and 4b are side views of other coatings (not to scale)incorporating a feature of the invention;

FIGS. 5a and 5b are side views of other coatings (not to scale)incorporating a feature of the invention;

FIGS. 6a, 6b, 6c, 6d, 6e, 6f, 6g, and 6h are side views of othercoatings (not to scale) incorporating a feature of the invention;

FIG. 7 is a graph showing the sheet resistance of ITO versus thicknessfor samples that had the surface of the ITO transparent conductive oxidelayer heated to specified temperatures.

FIGS. 8a-c are XRD graphs showing the crystallization of tin-dopedindium oxide transparent conductive oxide layers.

FIG. 9 shows the sheet resistance of a gallium-doped zinc oxidetransparent conductive oxide layer as deposited and have being heated.

FIG. 10 shows the sheet resistance of aluminum-doped zinc oxidetransparent conductive oxide layer as deposited and have being heated.

FIG. 11 is a graph showing the effect of the underlayer on the color ofa substrate having a 170 nm thick tin-doped indium oxide transparentconductive oxide layer.

FIG. 12 is a graph showing the effect of the underlayer on the color ofa substrate having a 175-225 nm thick tin-doped indium oxide transparentconductive oxide layer, and a silica protective layer.

FIG. 13a is a graph showing the effect of the embedded film on the sheetresistance.

FIG. 13b is a graph showing the effect of the embedded film onemissivity.

FIG. 13c is an XRD graph of indium-doped tin oxide having an embeddedfilm

FIG. 14 is a bar graph showing the durability of different protectivelayers.

FIG. 15 is a bar graph showing the durability of different protectivelayers.

FIGS. 16(a) and (b) are line graphs showing the normalized absorptionfor transparent conductive oxide layers comprising indium-doped tinoxide in an atmosphere with 0% to 2% oxygen.

FIG. 17(a) and b) are graphs showing the emissivity for transparentconductive oxide layers comprising indium-doped tin oxide in anatmosphere with 0% to 2% oxygen.

FIG. 18 is a graph showing the normalized absorbance for transparentconductive oxide layer comprising aluminum-doped zinc oxide in anatmosphere with 0% to 6% oxygen.

FIG. 19 is a graph showing normalized absorbance as a function of oxygencontent supplied to a coater.

FIG. 20 is a graph showing the sheet resistance for a transparentconductive oxide layer comprising indium-doped tin oxide afterpost-deposition processing as a function of the surface temperature ofthe transparent conductive oxide layer.

FIG. 21 is a graph showing sheet resistance as a function of the surfacetemperature of a transparent conductive oxide.

FIG. 22 is a graph showing the sheet resistance of ITO versus thicknessfor samples made with one ITO film or two ITO films which are depositedwhich are deposited on each other to get the thickness.

DESCRIPTION OF THE INVENTION

Spatial or directional terms used herein, such as “left”, “right”,“upper”, “lower”, and the like, relate to the invention as it is shownin the drawing figures. It is to be understood that the invention canassume various alternative orientations and, accordingly, such terms arenot to be considered as limiting.

As used herein, spatial or directional terms, such as “left”, “right”,“inner”, “outer”, “above”, “below”, and the like, relate to theinvention as it is shown in the drawing figures. However, it is to beunderstood that the invention can assume various alternativeorientations and, accordingly, such terms are not to be considered aslimiting. Further, as used herein, all numbers expressing dimensions,physical characteristics, processing parameters, quantities ofingredients, reaction conditions, and the like, used in thespecification and claims are to be understood as being modified in allinstances by the term “about”. Accordingly, unless indicated to thecontrary, the numerical values set forth in the following specificationand claims may vary depending upon the desired properties sought to beobtained by the present invention. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical value should at least be construedin light of the number of reported significant digits and by applyingordinary rounding techniques. Moreover, all ranges disclosed herein areto be understood to encompass the beginning and ending range values andany and all subranges subsumed therein. For example, a stated range of“1 to 10” should be considered to include any and all subranges between(and inclusive of) the minimum value of 1 and the maximum value of 10;that is, all subranges beginning with a minimum value of 1 or more andending with a maximum value of 10 or less, e.g., 1 to 3.3, 4.7 to 7.5,5.5 to 10, and the like. Additionally, all documents, such as but notlimited to, issued patents and patent applications, referred to hereinare to be considered to be “incorporated by reference” in theirentirety. Any reference to amounts, unless otherwise specified, is “byweight percent”. The term “film” refers to a region of a coating havinga desired or selected composition. A “layer” comprises one or more“films”. A “coating” or “coating stack” is comprised of one or more“layers”. The terms “metal” and “metal oxide” are to be considered toinclude silicon and silica, respectively, as well as traditionallyrecognized metals and metal oxides, even though silicon is technicallynot a metal.

All numbers used in the specification and claims are to be understood asbeing modified in all instances by the term “about”. All rangesdisclosed herein are to be understood to encompass the beginning andending range values and any and all subranges subsumed therein. Theranges set forth herein represent the average values over the specifiedrange.

The term “over” means “farther from the substrate”. For example, asecond layer located “over” a first layer means that the second layer islocated farther from the substrate than the first layer. The secondlayer can be in direct contact with the first layer or one or more otherlayers can be located between the second layer and the first layer.

All documents referred to herein are to be considered to be“incorporated by reference” in their entirety.

Any reference to amounts, unless otherwise specified, is “by weightpercent”.

The term “visible light” means electromagnetic radiation having awavelength in the range of 380 nm to 780 nm. The term “infraredradiation” means electromagnetic radiation having a wavelength in therange of greater than 780 nm to 100,000 nm. The term “ultravioletradiation” means electromagnetic energy having a wavelength in the rangeof 100 nm to less than 380 nm.

The terms “metal” and “metal oxide” include silicon and silica,respectively, as well as traditionally recognized metals and metaloxides, even though silicon may not be conventionally considered ametal. By “at least” is meant “greater than or equal to”. By “not morethan” is meant “less than or equal to”.

All haze and transmittance values herein are those determined using aHaze-Gard Plus haze meter (commercially available from BYK-Gardner USA)and in accordance with ASTM D1003-07.

In instances where percent oxygen is referenced in a coater, the percentoxygen is the amount of oxygen added to the coater chamber in relationto other gases. For example, if 2% oxygen is added to the coaterchamber's atmosphere, then 2% oxygen and 98% argon is added to thecoater chamber. Argon can be substituted for other gases, but often thegases are inert gases.

The discussion of the invention herein may describe certain features asbeing “particularly” or “preferably” within certain limitations (e.g.,“preferably”, “more preferably”, or “even more preferably”, withincertain limitations). It is to be understood that the invention is notlimited to these particular or preferred limitations but encompasses theentire scope of the disclosure.

The invention comprises, consists of, or consists essentially of, thefollowing aspects of the invention, in any combination. Various aspectsof the invention are illustrated in separate drawing figures. However,it is to be understood that this is simply for ease of illustration anddiscussion. In the practice of the invention, one or more aspects of theinvention shown in one drawing figure can be combined with one or moreaspects of the invention shown in one or more of the other drawingfigures.

An exemplary article includes a substrate 10, an underlayer 12 over thesubstrate 10 and a transparent conductive oxide 14 over the underlayer12 is shown in FIG. 1.

The article 2 can be a window, a solar mirror, a solar cell, or anorganic light emitting diode. The coating applied to the substrate 10can provide low emissivity, low resistivity, scratch resistance, radiofrequency attenuation or a desired color.

The substrate 10 can be transparent, translucent, or opaque to visiblelight. By “transparent” is meant having a visible light transmittance ofgreater than 0% up to 100%. Alternatively, the substrate 12 can betranslucent or opaque. By “translucent” is meant allowingelectromagnetic energy (e.g., visible light) to pass through butdiffusing this energy such that objects on the side opposite the viewerare not clearly visible. By “opaque” is meant having a visible lighttransmittance of 0%.

The substrate 10 can be glass, plastic or metal. Examples of suitableplastic substrates include acrylic polymers, such as polyacrylates;polyalkylmethacrylates, such as polymethylmethacrylates,polyethylmethacrylates, polypropylmethacrylates, and the like;polyurethanes; polycarbonates; polyalkylterephthalates, such aspolyethyleneterephthalate (PET), polypropyleneterephthalates,polybutyleneterephthalates, and the like; polysiloxane-containingpolymers; or copolymers of any monomers for preparing these, or anymixtures thereof); or glass substrates. Examples of suitable glasssubstrates include conventional soda-lime-silicate glass, borosilicateglass, or leaded glass. The glass can be clear glass. By “clear glass”is meant non-tinted or non-colored glass. Alternatively, the glass canbe tinted or otherwise colored glass. The glass can be annealed orheat-treated glass. As used herein, the term “heat treated” meanstempered or at least partially tempered. The glass can be of any type,such as conventional float glass, and can be of any composition havingany optical properties, e.g., any value of visible transmission,ultraviolet transmission, infrared transmission, and/or total solarenergy transmission. Examples of suitable metal substrates includealuminum or stainless steel.

The substrate 10 can have a high visible light transmission at areference wavelength of 550 nanometers (nm) and a thickness of 2millimeters. By “high visible light transmission” is meant visible lighttransmission at 550 nm of greater than or equal to 85%, such as greaterthan or equal to 87%, such as greater than or equal to 90%, such asgreater than or equal to 91%, such as greater than or equal to 92%.

The underlayer 12 can be a single layer, a homogeneous layer, a gradientlayer, a bi-layer or can include a plurality of layers. By “homogeneouslayer” is meant a layer in which the materials are randomly distributedthroughout the coating. By “gradient layer” is meant a layer having twoor more components, with the concentration of the components varying(continually changing or step change) as the distance from the substrate12 changes.

The underlayer 12 can include two films: a first underlayer film 20 anda second underlayer film 22. The first underlayer film 20 is positionedover the substrate 10, and is closer to the substrate 10 than the secondunderlayer film 22. The first underlayer film 20 can be a material thathas a higher refractive index than the second underlayer film 22 and/orthe substrate 10. For example, the first underlayer film 20 can comprisea metal oxide, nitride, or oxynitride. Examples of suitable metals forthe first underlayer film 20 include silicon, titanium, aluminum,zirconium, hafnium, niobium, zinc, bismuth, lead, indium, tin, tantalum,alloys thereof or mixtures thereof. For example, the first underlayerfilm 20 can include an oxide of zinc, tin, aluminum, and/or titanium,alloys thereof or mixtures thereof. For example, the first underlayerfilm 20 can include an oxide of zinc and/or tin. For example, the firstunderlayer film 20 can include zinc oxide and tin oxide, or zincstannate.

The first underlayer film 20 can include zinc oxide. A zinc target tosputter a zinc oxide film may include one or more other materials toimprove the sputtering characteristics of the zinc target. For example,the zinc target can include up to 15 wt. %, such as up to 10 wt. %, suchas up to 5 wt. %, of such a material. The resultant zinc oxide layerwould include a small percentage of an oxide of the added material,e.g., up to 15 wt. %, up to 10 wt. %, up to 9 wt. % of the materialoxide. A layer deposited from a zinc target having up to 10 wt. %, e.g.,up to 5 wt. % of an additional material to enhance the sputteringcharacteristics of the zinc target is referred to herein as “a zincoxide layer” even though a small amount of the added material (or anoxide of the added material) may be present. An example of such amaterial is tin.

The first underlayer film 20 can include an alloy of zinc oxide and tinoxide. For example, the first underlayer film 20 can include or can be azinc stannate layer. By “zinc stannate” is meant a composition of theformula: Zn_(x)Sn_(1-x)O_(2-x) (Formula 1) where “x” varies in the rangeof greater than 0 to less than 1. For instance, “x” can be greater than0 and can be any fraction or decimal between greater than 0 to lessthan 1. A zinc stannate layer has one or more of the forms of Formula 1in a predominant amount. A zinc stannate layer in which x=⅔ isconventionally referred to as “Zn₂SnO4”. The alloy of zinc oxide and tinoxide can include 80 wt % to 99 wt % zinc and 20 wt % to 1 wt % tin;such as 85 wt % zinc to 99 wt % zinc and 15 wt % tin to 1 wt % tin; 90wt % zinc to 99 wt % zinc and 10 wt % tin to 1 wt % tin; such asapproximately 90 wt % zinc and 10 wt % tin.

The second underlayer film 22 can be a material that has a lowerrefractive index than the first underlayer film 20. For example, thesecond underlayer film 22 can comprise a metal oxide, nitride, oroxynitride. Examples of suitable metals for the second underlayer filminclude silicon, titanium, aluminum, zirconium, phosphorus, hafnium,niobium, zinc, bismuth, lead, indium, tin, tantalum alloys thereof ormixtures thereof.

For example, the second underlayer film 22 can include silica andalumina. According to this example, the second underlayer film 22 wouldhave at least 50 weight % silica; 50 to 99 weight % silica and 50 to 1weight % alumina; 60 to 98 weight % silica and 40 to 2 weight alumina;70 to 95 weight % silica and 30 to 5 weight % alumina; 80 to 90 weight %silica and 10 to 20 weight % alumina, or 8 weight % silica and 15 weight% alumina.

A transparent conductive oxide layer 14 is over the underlayer 12. Thetransparent conductive oxide layer 14 can be a single layer or can havemultiple layers or regions. The transparent conductive oxide layer 14has at least one conductive oxide layer. For example, the transparentconductive oxide layer 14 can include one or more metal oxide materials.For example, the transparent conductive oxide layer 14 can include oneor more oxides of one or more of Zn, Fe, Mn, Al, Ce, Sn, Sb, Hf, Zr, Ni,Bi, Ti, Co, Cr, Si, In, or an alloy of two or more of these materials.For example, the transparent conductive oxide layer 14 can comprise tinoxide. In another example, the transparent conductive oxide layer 14comprises zinc oxide

The transparent conductive oxide layer 14 can include one or more dopantmaterials, such as, but not limited to, F, In, Al, P, Cu, Mo, Ta, Ti,Ni, Nb, W, Ga, Mg, and/or Sb. For example, the dopant can be In, Ga, Alor Mg. The dopant can be present in an amount less than 10 wt. %, suchas less than 5 wt. %, such as less than 4 wt. %, such as less than 2 wt.%, such as less than 1 wt. %. The transparent conductive oxide layer 14can be a doped metal oxide such as gallium-doped zinc oxide (“GZO”),aluminum-doped zinc oxide (“AZO”), indium-doped zinc oxide (“IZO”)magnesium-doped zinc oxide (“MZO”), or tin-doped indium oxide (“ITO”).

The transparent conductive oxide layer 14 can have a thickness in therange of 75 nm to 950 nm, such as 90 nm to 800 nm, such as 100 nm to 700nm. For example, the transparent conductive oxide layer 14 can have athickness in the range of 125 nm to 450 nm; at least 150 nm; or at least175 nm. The transparent conductive oxide layer 14 can have a thicknessthat is no greater than 600 nm, 500 nm, 400 nm, 350 nm, 300 nm, 275 nm,250 nm, or 225 nm.

Different transparent conductive oxide layer 14 materials have differentsheet resistance at the same thickness, and impact the optics of thearticle differently, as well. Ideally, the sheet resistance should beless than 25Ω/□ ohms per square, or less than 20Ω/□, or less than 18ω/□. For example, if the transparent conductive oxide layer 14 comprisesGZO, it can have a thickness of at least 300 nm, and at most 400 nm. Ifthe transparent conductive oxide layer 14 comprises AZO, it should havea thickness of at least 350 nm, or at least 400 nm, and a thickness atmost 950 nm, or at most 800 nm, or at most 700 nm, or at most 600 nm. Ifthe transparent conductive oxide layer 14 comprises ITO, it can have athickness of at least 75 nm, at least 90 nm, at least 100 nm, at least125 nm, or at least 150 nm, or at least 175 nm; and at most 350 nm, atmost 300 nm, at most 275 nm, or at most 250 nm, or at most 225 nm.

The transparent conductive oxide layer 14 can have a surface roughness(RMS) in the range of 5 nm to 60 nm, such as 5 nm to 40 nm, such as 5 nmto 30 nm, such as 10 nm to 30 nm, such as 10 nm to 20 nm, such as 10 nmto 15 nm, such as 11 nm to 15 nm.

For example, when the transparent conductive oxide layer 14 is tin-dopedindium oxide, the thickness of the transparent conductive oxide layer 14can be in the range of 75 nm to 350 nm; 100 nm to 300 nm; 125 nm to 275nm; 150 nm to 250 nm; or 175 nm to 225 nm.

The transparent conductive oxide layer 14 can have a sheet resistance inthe range of 5Ω/□ to 25Ω/□, such as 8Ω/□ to 20Ω/□. For example, such as10Ω/□ to 18 ω/□.

For example, the article can be a glass substrate 10 with an underlayer12 over the glass substrate 10. The underlayer 12 can have at least twofilms: a first underlayer film 20 and a second underlayer film 22. Thefirst underlayer film 20 can be an alloy of zinc oxide and tin oxide,and the second underlayer film 22 and can be an alloy of silica andalumina. A transparent conductive oxide layer 14 can be over the secondfilm 22. The transparent conductive oxide layer 14 can be ITO, GZO orAZO.

The transparent conductive oxide film provides that article with acertain sheet resistance, for example, less than 25Ω/□. Generally, asthe thickness of the transparent conductive oxide increase, the sheetresistance decrease. Once the desired sheet resistance is identified andthe necessary thickness for the transparent conductive oxide to achievethe desired sheet resistance, optical design software can be used todetermine the thickness of the first film and the second film. Anexample of a suitable optical modelling software is FILM STAR. Ideally,one strives to have a color of a*, b* be −1, −1. Some variability, isacceptable in this color. For example, the a* can be as high as 1, 0 or−0.5 and as low as −9, −4, −3 or −1.5 and the b* value can be as high as1, 0 or −0.5 and as low as −9, −4, −3 or −1.5. To obtain the desiredcolor, one changes the thickness of the first film 20 and the secondfilm 22 to obtain the desired color for the identified transparentconductive oxide and thickness of the transparent conductive oxide. Forexample, the first film may be between 10 and 20 nm thick, or between 11and 15 nm thick; and the second film may be between 25 and 35 nm thick,or between 29 and 34 nm thick.

Referring to FIGS. 1c and 1d , the article 2 may optionally include aprotective layer 16 over the transparent conductive oxide layer 14, suchas the protective layer as described herein. For example, the protectivelayer 16 may include a first protective film 60 and a second protectivefilm 62. The second protective film 62 may include a mixture of titaniaand silica. For example, the protective layer 16 have included a firstprotective film 60, a second protective film 62 and a third protectivefilm 64.

An exemplary method of the invention is forming a coated substrate. Asubstrate 10 is provided. A transparent conductive oxide is identified.Once the transparent conductive oxide is identified, one can identify athickness for the transparent conductive film that will provide thecoated substrate with a sheet resistance of at least 5Ω/□ and/or no morethan 25Ω/□, specifically no more than 20Ω/□, more specifically no morethan 18Ω/□. A desired color of the coated substrate is also identified.A first underlayer material and a second underlayer material areidentified using optical design software, a first underlayer filmthickness and a second underlayer film thickness are determined thatwill provide the article having the above-identified transparentconductive oxide layer with a color wherein a* can be as high as 1 andas low as −9, and the b* value can be as high as 1 and as low as −9. Theunderlayer 12 is applied over the substrate by applying the firstunderlayer material over the substrate to form a first underlayer film20 to the identified first film thickness, and applying the secondunderlayer material over the first underlayer film to the identifiedsecond underlayer film thickness to form the second underlayer film 22.The transparent conductive oxide material is applied over the underlayer12 to the identified transparent conductive film thickness to form thetransparent conductive oxide layer 14.

The thickness of the transparent conductive oxide layer 14 impacts thesheet resistance and the color of a substrate. The underlayer 12 is usedto tune the color of the article having the transparent conductive oxidelayer 14 at a specific thickness. This is done by identifying a firstunderlayer material and a second underlayer material, then, using a toolsuch as FILM STAR, identifying thicknesses for each underlayer materialthat provide the desired color. Once the first and second underlayermaterials are identified, one can tune the thickness of each of thesematerials to achieve any desired color. Typically, a desired color isa*, b* be −1, −1. Some variability, is acceptable in this color. Forexample, the a* can be as high as 1 and as low as −9, and the b* valuecan be as high as 1 and as low as −9.

For example, one may wish to make a solar cell having a color of a* −1and b* −1. A glass substrate would be provided. The transparentconductive oxide material could be identified as indium doped tin oxide(“ITO”). One would understand that if the thickness of the ITOtransparent conductive oxide film is between 125 nm and 275 nm, one canachieve a sheet resistance of 5Ω/□ to 25Ω/□ with the invention disclosedherein. In order to achieve the desired color, one could select anunderlayer 12 that has a first underlayer film 20 comprising zinc oxideand tin oxide, and a second underlayer film 22 comprising silica andalumina. The first underlayer film 20 would have a thickness between 10nm and 15 nm, and the second underlayer film 22 would have a thicknessbetween 29 nm and 34 nm. The first underlayer film 20 is applied overthe substrate 10 at the identified thickness, and the second underlayerfilm 22 is applied over the first underlayer film 20 at the identifiedthickness. The transparent conductive oxide layer 14 is applied over thesecond underlayer film 22 at the identified thickness, thus forming anarticle having a color with an a* between −9 to 1, specifically between−4 and 0, more specifically between −3 and 1, more specifically between−1.5 and −0.5; and b* between −9 to 1, specifically between −4 and 0,more specifically between −1.5 and −0.5.

In another example, a glass substrate 10 would be provided. Thetransparent conductive oxide layer material could be identified asindium doped tin oxide (“ITO”). One would understand that if thethickness of the ITO transparent conductive oxide film is between 125 nmand 275 nm, one would achieve a sheet resistance of 5Ω/□ to 25Ω/□,specifically no more than 20Ω/□, more specifically no more than 18 ω/□.In order to achieve the desired color, one could select an underlayer 12that has a first underlayer film 20 comprising zinc oxide and tin oxide,and a second underlayer film 22 comprising silica, and also consider theeffect on the color that the protective layer 16 would have on thecoated substrate. In this example, a protective layer of silica having athickness of at least 30 nm and no more than 45 nm is used. The firstunderlayer film 20 would have a thickness between 10 nm and 15 nm, andthe second underlayer film 22 would have a thickness between 29 nm and34 nm. The first underlayer film 20 is applied over the substrate 10 atthe identified thickness, and the second underlayer film 22 is appliedover the first underlayer film 20 at the identified thickness. Thetransparent conductive oxide layer 14 is applied over the secondunderlayer film 22 at the identified thickness that provides the sheetresistance discussed above, thus forming a coated substrate having acolor between a* −9 to 1, or −4 to 0, or −3 to 1, or −1.5 to −0.5 and b*−9 to 1; or −4 to 0, or −3 to 1, or −1.5 to −0.5.

In these examples, the underlayer is used to tune the color of thecoated substrate.

FIG. 2 shows another exemplary article 2 that includes a substrate 10,an underlayer 12 over the substrate a transparent conductive oxide layer14 over the underlayer 12 and an embedded film 24 comprising a secondhigh refractive index material that is embedded in the transparentconductive oxide layer 14.

The substrate 10 can be any of the substrates discussed herein.

The underlayer 12 can have a first underlayer film 20 and an optionalsecond underlayer film 22. The first underlayer film 20 has a first highrefractive index material. The optional second underlayer film 22 has afirst low refractive index material. The first high refractive indexmaterial has a refractive index higher than the first lower refractiveindex material.

The transparent conductive oxide layer 14 can be any of the transparentconductive oxides discussed above.

The embedded film 24 has a second high refractive index materialembedded within the transparent conductive oxide layer 14. The secondhigh refractive index material can be any material that has a higherrefractive index than the first low refractive index material. Forexample, the second high refractive index material forming the embeddedfilm 24 can comprise a metal oxide, nitride, or oxynitride. Examples ofsuitable oxide materials for the embedded film 24 include oxides ofsilicon, titanium, aluminum, zirconium, phosphorus, hafnium, niobium,zinc, bismuth, lead, indium, tin, and/or alloys and/or mixtures thereof.For example, the embedded film 24 can include an oxide of silicon and/oraluminum.

For example, the embedded film 24 can include an oxide of silicon andaluminum. According to this example, the second underlayer film 22 wouldhave at least 50 volume % silica; 50 to 99 volume % silica and 50 to 1volume % alumina; 60 to 98 volume % silica and 40 to 2 volume % alumina;70 to 95 volume % silica and 30 to 5 volume % alumina; 80 to 90 weight %silica and 10 to 20 weight % alumina, or 8 weight % silica and 15 weight% alumina.

The embedded film 24 can have a thickness in the ranges of 5 nm to 50nm, 10 to 40 nm or 15 to 30 nm.

The article may optionally include a protective layer 16 over thetransparent conductive oxide layer 14, such as the protective layer isdescribed herein. For example, the protective layer 16 may include afirst protective film 60 and a second protective film 62. The secondprotective film 62 may include a mixture of titania and silica. Forexample, the protective layer 16 includes a first protective film 60, asecond protective film 62 and a third protective film 64.

FIG. 3 shows another exemplary article 2 that includes a substrate 10,an underlayer 12 over the substrate, a first transparent conductiveoxide layer 114 over the underlayer 12, an embedded film 124 over thefirst transparent conductive oxide layer 114. A second transparentconductive oxide layer 115 over the embedded film 124. Optionally, aprotective layer 16 can be applied over the second transparentconductive oxide layer 115.

The embedded film 124 can comprise a metal oxide, nitride, oroxynitride. Examples of suitable materials for the second highrefractive index metal include oxides of silicon, titanium, aluminum,zirconium, phosphorus, hafnium, niobium, zinc, bismuth, lead, indium,tin, and/or alloys and/or mixtures thereof. For example, the second highrefractive index material can include silica and/or alumina.

For example, the embedded film 124 can include silica and alumina. Thesecond high refractive index material would have at least 50 volume %silica; 50 to 99 volume % silica and 50 to 1 volume alumina; 60 to 98volume % silica and 40 to 2 volume % alumina; or 70 to 95 volume %silica and 30 to 5 volume % alumina; 80 to 90 weight silica and 10 to 20weight % alumina, or 8 weight % silica and 15 weight % alumina.

The embedded film 124 can have a thickness in the ranges of 5 nm to 50nm, 10 to 40 nm or 15 to 30 nm.

The first transparent conductive oxide layer 114 and the secondtransparent conductive oxide layer 115 have a combined thickness of inthe range of 75 nm to 950 nm, such as 90 nm to 800 nm, such as 125 nm to700 nm. For example, the combined thickness can be no greater than 950nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 350 nm, 300 nm, 275 nm, 250nm, or 225 nm. The combined thickness can be at least 75 nm, at least 90nm, at least 100 nm, at least 125 nm, 150 nm or 175 nm. The firsttransparent conductive oxide layer 114 can have a thickness of at least10 nm, at least 25 nm, 50 nm, 75 nm or 100 nm; and at most 650 nm, 550nm, 475 nm, 350 nm, 250 nm or 150. The second transparent conductiveoxide layer 115 can have a thickness of at least 10 nm, at least 25 nm,50 nm, 75 nm or 100 nm; and at most 650 nm, 550 nm, 475 nm, 350 nm, 250nm or 150. For example, if the first transparent conductive oxide layer114 and the second transparent conductive oxide layer 115 comprises ITO,the first transparent conductive oxide layer 114 can have a thickness ofat least 25 nm, 50 nm, 75 nm or 100 nm; and at most 200 nm, 175 nm, 150nm or 125 nm; and the second transparent conductive oxide layer 115 canhave a thickness of at least 25 nm, 50 nm, 75 nm or 100 nm; and at most200 nm, 175 nm, 150 nm or 125 nm. In another example, if transparentconductive oxide layer 114 and the second transparent conductive oxidelayer 115 comprises AZO, the first transparent conductive oxide layer114 can have a thickness of at least 100 nm, at least 150 nm at least200 nm, 250 nm, or 300 nm; and at most 650 nm, 550 nm, at most 450 nm,at most 325 nm or at most 200 nm; and the second transparent conductiveoxide layer 115 can have a thickness of at least 100 nm, at least 150 nmat least 200 nm, 250 nm, or 300 nm; and at most 650 nm, 550 nm, at most450 nm, at most 325 nm or at most 200 nm. In another example, iftransparent conductive oxide layer 114 and the second transparentconductive oxide layer 115 comprises GZO, the first transparentconductive oxide layer 114 can have a thickness of at least 30 nm, atleast 60 nm, at least 75 nm, at least 90 nm, at least 100 nm, at least125 nm, at least 150 nm, 200 nm, or 300 nm; and at most 350 nm, at most300 nm, 275 nm, at most 250 nm, or at most 225 nm; and the secondtransparent conductive oxide layer 115 can have a thickness of at least30 nm, at least 60 nm, at least 75 nm, at least 90 nm, at least 100 nm,at least 125 nm, at least 150 nm, 200 nm, or 300 nm; and 350 nm, at most300 nm, 275 nm, at most 250 nm, or at most 225 nm.

By changing the thickness of the first and second transparent conductiveoxide layers 114, 115, one moves the embedded film 124 either higher inthe transparent conductive oxide layer 14, or lower in the transparentconductive oxide layer 14. Surprisingly, no matter where the embeddedfilm 24, 124 is positioned within the coating stack, there is asignificant increase in the sheet resistance (see FIG. 13a ). Alsosurprisingly, the position of the embedded film 24, 124 within thetransparent conductive oxide layer 14 has a different impact on thelight transmission (see FIG. 13b ). When the first transparentconductive oxide layer 114 is thinner than the second transparentconductive oxide layer 115, thereby the embedded film 124 is positionedlower within the transparent conductive oxide layer 14, there is anincrease in light transmission (see FIG. 13b ). This increase is morepronounced when the first transparent conductive oxide layer 114 isthicker than the second transparent conductive oxide layer 115, therebythe embedded film 124 is positioned higher within the transparentconductive oxide layer 14 (see FIG. 13b ). However, if the thickness ofthe first transparent conductive oxide layer 114 is approximately equalto the thickness of the second transparent conductive oxide layer 115,thereby the embedded film 124 is positioned at approximately the middleof the transparent conductive oxide layer 14, the transmission decreases(see FIG. 13b ). For example, the second transparent conductive oxidefilm 115 can be at least 25%, at least 50%, at least 75%, at least 100%(i.e. at least doubled), at least 125% or at least 150% thicker than thefirst transparent conductive oxide film 114; and can be at most 250%thicker; at most 200% thicker; at most 150% thicker; at most 125%thicker; at most 100% (i.e. at most doubled) thicker; at most 75%thicker; at most 50% thicker or at most 25% thicker than the firsttransparent conductive oxide film 114. Alternatively, the secondtransparent conductive oxide film 115 can be at least 25%, at least 50%,at least 75%, at least 100% (i.e. at least doubled), at least 125% or atleast 150% thinner than the first transparent conductive oxide film 114;and can be at most 250% thinner; at most 200% thinner; at most 150%thinner; at most 125% thinner; at most 100% (i.e. at most doubled)thinner; at most 75% thinner; at most 50% thinner or at most 25% thinnerthan the first transparent conductive oxide film 114.

Another example of the invention is a method of making a coated article2. A substrate 10 is provided. A first underlayer film 20 having a firsthigh refractive index material is applied over at least a portion of thesubstrate 10. A second underlayer film 22 having a first low refractiveindex material is applied over at least a portion of the firstunderlayer film 20, wherein the first lower refractive index materialhas a refractive index that is lower than the first high refractiveindex film. A first transparent conductive oxide film 114 is appliedover at least a portion of the underlayer 12. An embedded film 124having a second high refractive index material is applied over at leasta portion of the first transparent conductive oxide film 114, whereinthe second high refractive index material has a refractive index that isgreater than the first low refractive index material, or has arefractive index that is within 10%, or 5% of the refractive index forthe first high refractive index, or is the same material as the firsthigh refractive index material, or has the same refractive index as thefirst high refractive index material. A second transparent conductiveoxide film 115 is applied over at least a portion of the embedded film124. The second high refractive index film splits the transparentconductive oxide film into two portions, the first transparentconductive oxide film and the second transparent conductive oxide film.

The embedded film 124 also allows one to tune a color for the coatedsubstrate. The color can have an a* of at least −9, −4, −3 or −1.5 andat most 1, 0 or −0.5 and have a b* of at least −9, −4, −3 or −1.5 and atmost 1, 0 or −0.5.

By changing the thicknesses of the two high refractive index materials,and the low refractive index material, one can tune the color of thecoated substrate. To this end, first, one should identify the materialthat will be used in the transparent conductive oxide films 114 and 115.Once that material is identified, a desired sheet resistance isidentified. By knowing the material and the sheet resistance, one candetermine the thickness of the transparent conductive oxide layer 14, orthe combined thickness of the first and second transparent conductiveoxide films 114 and 115. The transparent conductive oxide layer 14 willimpact the color of the coated substrate. To offset this color impact,one can use an optical design tool (e.g. FILM STAR) to identify thethicknesses for the first and second underlayer films 20 and 22, and thethickness of the embedded film 24, 124. This is done by inputting thethickness of the transparent conductive oxide layer 14 into thesoftware, identifying the first high refractive index material, secondhigh refractive index material and first lower refractive indexmaterial. With these parameters, one can determine the thickness of thefirst and second underlayer films 20 and 24, and the embedded film 24,124. These films are then applied at those identified thicknesses.

For example, the method may include identifying a first transparentconductive oxide material to be used in the first transparent conductiveoxide film 114, and a second transparent conductive oxide material to beused in the second transparent conductive oxide 115. These transparentconductive oxides can be GZO, AZO, IZO, MZO, or ITO.

A thickness for the transparent conductive oxide layer 14 can beidentified by first identifying a desired sheet resistance. Once thesheet resistance is identified, one can then identify the combinedthickness of both transparent conductive oxide films 114, 115. The sheetresistance can be at least 8Ω/□, at least 10Ω/□, or at least 12Ω/□; andcan be at most 25Ω/□, at most 20Ω/□, or at most 18Ω/□. To achieve thosevalues, the combined thickness of the transparent conductive oxide layer14 can be at least 75 nm, at least 90 nm, at least 100 nm; at least 175nm; at least 180 nm; at least 190 nm; at least 200 nm; at least 205 nm;at least 225 nm; or at least 360 nm. Since the transparent conductiveoxide layer 14 impacts the color of the coated substrate, it isimportant to minimize the combined thickness of the transparentconductive oxide films 114, 115. To this end, the combined thickness ofthe transparent conductive oxide films 114, 115 can be at most 800 nm;at most 700 nm; at most 360 nm; at least 350 nm, at most 300 nm, at most275 bnm, at most 250 nm, at most 225 nm; at most 205 nm; at most 200 nm;at most 190 nm; at most 180 nm or at most 175 nm.

One also determines the position of the embedded film 24,124 within thetransparent conductive oxide. In doing so, one considers whether onedesires to have increase or decrease transmission (see FIG. 13(b)). Thefirst transparent conductive oxide film 114 can be thicker, thinner orabout the same thickness as the second conductive oxide film 115.

A first high refractive index material for a first underlayer film 20, afirst low refractive index material for a second underlayer film 22 anda second high refractive index material for embedded film 24,124 areidentified. Optionally a protective layer 16 may be identified withidentified thickness for each protective layer film 60, 62 and/or 64. Adesired color is identified. Those parameters are inputted into anoptical design tool, such as FILM STAR, and thickness for the firstunderlayer film 20 and underlayer film 22 and embedded film 124 areidentified.

The coating stack having the underlayer 12, transparent conductive oxidelayer 14, embedded film 24,124 and optional protective layer 16 areapplied over the substrate at the identified thickness. The thickness ofthe underlay films 20, 22 and embedded film 24,124 tune the color of thearticle 2 to the desired color

FIGS. 4a and 4b shows another exemplary article 2 that includes asubstrate 10, an underlayer 12 over the substrate 10, a transparentconductive oxide layer 14 over the underlayer 12, and a protective layer16 over the transparent conductive oxide layer 14. The substrate 10,underlayer 12, and transparent conductive oxide layer 14 can be any ofsubstrates or underlayers discussed herein. The transparent conductiveoxide layer 14 can be divided by the embedded layers 24,124 discussedherein.

The protective layer 16 is over the transparent conductive oxide layer14, or optionally in direct contact with the transparent conductiveoxide layer 14. It can include at least two protective films 60, 62 orat least three protective films 60, 62, 64.

FIG. 4a shows an example of an article with a protective layer havingtwo protective films 60, 62. The first protective film 60 is positionedover the transparent conductive oxide layer 14, and is closer to thetransparent conductive oxide layer 14 than the second protective film62. The second protective film 62 is the outer most film in the coating18 on the coated article.

The first protective film 60 can comprise alumina, silica, titania,zirconia, tin oxide or mixtures thereof. For example, the firstprotective film can comprise a mixture of silica and alumina. In anotherexample, the first protective film 60 can comprise zinc stannate. Inanother example, the first protective film 60 can comprise zirconia.

The second protective film 62 comprises a mixture of titania andalumina. The second protective film 62 is the last film in a coating 18applied over the substrate 10.

The second protective film 62 comprises 40-60 weight percent of alumina,and 60-40 weight percent of titania; 45-55 weight percent of alumina,and 55-45 weight percent of titania; 48-52 weight percent of alumina,and 52-48 weight percent of titania; 49-51 weight percent of alumina,and 51-49 weight percent of titania; or 50 weight percent of alumina,and 50 weight percent of titania.

As shown in FIG. 4b , the protective layer 16 may further comprise athird protective film 64 positioned between the first protective film 60and the second protective film 62. The third protective film 64 cancomprise alumina, silica, titania, zirconia, tin oxide or mixturesthereof. For example, the third protective film 64 can comprise amixture of silica and alumina. In another example, the third protectivefilm 64 comprises zinc stannate. In another example, the thirdprotective film 64 comprises zirconia.

Another exemplary article is shown in FIGS. 5a and b , which includes asubstrate 10, a functional coating 112 and a protective layer 16. Thesubstrate in this method may be glass, plastic or metal.

The functional coating 112 can be any functional coating. For example,it can include multiple dielectric films or multiple metal films. Thefunction coating can include the underlayer 12 described herein, and/orthe transparent conductive oxide layer 14 described herein. Theprotective layer 16 can be a first protective film 60 and a secondprotective film 62 as described herein. In this instance, the secondprotective film 62 is the outer most film, and includes alumina andtitania.

The protective layer can have a total thickness of at least 20 nm, 40nm, 60 nm, or 80 nm, 100 nm or 120 nm; and at most 275 nm, 255 nm, 240nm, 170 nm, 150 nm, 125 nm or 100 nm. The first protective film can havea thickness of at least 10 nm, at least 15 nm at least 27 nm, at least35 nm, at least 40 nm, at least 54 nm, at least 72 nm; and at most 85nm, 70 nm, 60 nm 50 nm, 45 nm, 30 nm. The second protective film canhave a thickness of at least 10 nm, at least 15 nm at least 27 nm, atleast 35 nm, at least 40 nm, at least 54 nm, at least 72 nm; and at most85 nm, 70 nm, 60 nm 50 nm, 45 nm, 30 nm. The optional third protectivefilm can have a thickness of at least 10 nm, at least 15 nm at least 27nm, at least 35 nm, at least 40 nm, at least 54 nm, at least 72 nm; andat most 85 nm, 70 nm, 60 nm 50 nm, 45 nm, 30 nm. For example, theprotective layer can have the thickness listed in Table 1, below. In oneembodiment, the 1st protective film has a thickness of at least 20 nm orat least 30 nm; and at most 60 nm or at most 50 nm. The secondprotective film has a thickness of at least 15 nm, or at least 20 nm;and at most 50 nm or at most 40 nm. The optional third protective layerhas a thickness of at least 5 nm, or at least 10 nm; and at most 30 nmor at most 20 nm. The optional third protective layer may be positionedbetween the first protective film and the functional layer, or betweenthe first protective film and the second protective film.

TABLE 1 Exemplary Thickness for a Protective Layer 1^(st) Optional3^(rd) 2^(nd) Protective Film Protective Film Protective Film 27 nm — 33nm 27 nm — 50 nm 27 nm — 68 nm 27 nm — 85 nm 54 nm — 33 nm 54 nm — 50 nm54 nm — 68 nm 54 nm — 85 nm 72 nm — 33 nm 72 nm — 50 nm 72 nm — 68 nm 72nm — 85 nm 50 nm — 50 nm 50 nm — 70 nm 50 nm — 85 nm 70 nm — 50 nm 70 nm— 70 nm 70 nm — 85 nm 20 nm — 20 nm 20 nm — 30 nm 20 nm — 40 nm 30 nm —20 nm 30 nm — 30 nm 30 nm — 40 nm 40 nm — 20 nm 40 nm — 30 nm 40 nm — 40nm 50 nm 15 nm 50 nm 50 nm 15 nm 70 nm 50 nm 15 nm 85 nm 70 nm 15 nm 50nm 70 nm 15 nm 70 nm 70 nm 15 nm 85 nm 15 nm 50 nm 50 nm 15 nm 50 nm 70nm 15 nm 50 nm 85 nm 15 nm 70 nm 50 nm 15 nm 70 nm 70 nm 15 nm 70 nm 85nm

The functional coating 112 can be a single film functional coating orcan be a multi-film functional coating that includes a one or moredielectric layers and/or one or more infrared reflective layers.

The functional coating 112 can, for example, be a solar control coating.The term “solar control coating” refers to a coating comprised of one ormore layers or films that affect the solar properties of the coatedarticle, such as, but not limited to, the amount of solar radiation, forexample, visible, infrared, or ultraviolet radiation, reflected from,absorbed by, or passing through the coated article; shading coefficient;emissivity, etc. The solar control coating can block, absorb, or filterselected portions of the solar spectrum, such as, but not limited to,the IR, UV, and/or visible spectrums.

The functional coating 112 can, for example, include one or moredielectric films. The dielectric film can comprise an anti-reflectivematerial, including, but not limited to, metal oxides, oxides of metalalloys, nitrides, oxynitrides, or mixtures thereof. The dielectric filmcan be transparent to visible light. Examples of suitable metal oxidesfor the dielectric film include oxides of titanium, hafnium, zirconium,niobium, zinc, bismuth, lead, indium, tin, and mixtures thereof. Thesemetal oxides can have small amounts of other materials, such asmanganese in bismuth oxide, tin in indium oxide, etc. Additionally,oxides of metal alloys or metal mixtures can be used, such as oxidescontaining zinc and tin (e.g., zinc stannate, defined below), oxides ofindium-tin alloys, silicon nitrides, silicon aluminum nitrides, oraluminum nitrides. Further, doped metal oxides, such as antimony orindium doped tin oxides or nickel or boron doped silicon oxides, can beused. The dielectric film can be a substantially single phase film, suchas a metal alloy oxide film, e.g., zinc stannate, or can be a mixture ofphases composed of zinc and tin oxides or can be composed of a pluralityof films.

The functional coating 112 can include a radiation reflective film. Theradiation reflective film can include a reflective metal, such as, butnot limited to, metallic gold, copper, palladium, aluminum, silver, ormixtures thereof. In one embodiment, the radiation reflective filmcomprises a metallic silver layer.

In one embodiment, the functional coating comprises a first dielectriclayer 120 over the substrate 10, a second dielectric layer 122 over thefirst dielectric layer 120, and a metal layer 126 either between thefirst dielectric layer and second dielectric layer 120 (see FIG. 7) orover the second dielectric layer 122 (see FIG. 6a ). The protectivecoating 16 is positioned over the metal layer 126 (see FIG. 6b ).Optionally, a primer 128 may be applied between the metal film and thefirst dielectric layer (see FIG. 6c ) or the second dielectric layer(see FIG. 6d ).

The dielectric films 120 and 122 can be transparent to visible light.Examples of suitable metal oxides for the dielectric films 120 and 122include oxides of titanium, hafnium, zirconium, niobium, zinc, bismuth,lead, indium, tin, and mixtures thereof. These metal oxides can havesmall amounts of other materials, such as manganese in bismuth oxide,tin in indium oxide, etc. Additionally, oxides of metal alloys or metalmixtures can be used, such as oxides containing zinc and tin (e.g., zincstannate, defined above), oxides of indium-tin alloys, silicon nitrides,silicon aluminum nitrides, or aluminum nitrides. Further, doped metaloxides, such as antimony or indium doped tin oxides or nickel or borondoped silicon oxides, can be used. The dielectric films 120 and 122 canbe a substantially single phase film, such as a metal alloy oxide film,e.g., zinc stannate, or can be a mixture of phases composed of zinc andtin oxides. The dielectric films 120 and 122 can have a combinedthickness in the range of 100 Å to 600 Å, such as 200 Å to 500 Å, suchas 250 Å to 350 Å.

The metal film 126 may be selected from the group consisting of metallicgold, copper, palladium, aluminum, silver, and alloys thereof. Forexample, the metal film 126 can be silver.

The optional primer 128 can be a single film or multiple films. Forexample, the primer 128 can include an oxygen-capturing material thatcan be sacrificed during the deposition process to prevent degradationor oxidation of the metal film 126 during the sputtering process orsubsequent heating processes. The primer 128 can also absorb at least aportion of electromagnetic radiation, such as visible light, passingthrough the coating. Examples of materials useful for the primer 128include titanium, silicon, silicon dioxide, silicon nitride, siliconoxynitride, nickel-chrome alloys (such as lnconel), zirconium, aluminum,alloys of silicon and aluminum, alloys containing cobalt and chromium(e.g., Stellite®), and mixtures thereof. For example, the primer 148 canbe titanium.

The protective layer 16 can include a first protective film 60 and asecond protective film 62; or a first protective film 60 (see FIGS. 5aand 6a-d ), a second protective film 62 and a third protective film 64(see FIGS. 5b and 6e-h ).

In a method for making a coated article, an underlayer 12 is appliedover a substrate 10, and a transparent conductive oxide layer 14 isapplied over the underlayer 12. The undercoating 12 can be applied overthe substrate 10, and the transparent conductive oxide layer 14 can beapplied over at least a portion of the underlayer 12; or a substrate 10having the undercoating 12 and the transparent conductive oxide layer 14on it can be provided. A protective layer 16 is applied over at least aportion of the transparent conductive oxide. The protective layer 16 isapplied by first applying a first protective film 60 over thetransparent conductive oxide, and then applying a second protective film62 over the first protective film 60. Optionally, a third protectivefilm 64 can be applied over the first protective film 60, and the secondprotective film 62 can be applied over the third protective film 64.

In a method for making a coated article, a functional coating 112 isapplied over a substrate 10. A functional coating 112 can be appliedover the substrate 10, or a substrate having a functional coating 112can be provided. A protective layer 16 is applied over the functionalcoating 112. The protective layer 16 is applied by first applying afirst protective film 60 over the transparent conductive oxide, and thenapplying a second protective film 62 over the first protective film 60.Optionally, a third protective film 64 can be applied over the firstprotective film 60, and the second protective film 62 can be appliedover the third protective film 64.

Another exemplary method of the invention is a method of increasing thesheet resistance of a coated article. A coated article is provided. Thecoated article has a substrate and transparent conductive oxide layerover at least part of the substrate. The coated article is processedwith a post-deposition process.

The post-deposition process can be tempering the coated article, flashannealing only a surface of the transparent conductive oxide layer, orpassing an Eddy current through the transparent conductive oxide layer.

Tempering the coated article is done by heating the entire article sothat the surface of the transparent conductive oxide layer reaches above380° F., at least 435° F., or at least 635° F. for at least 5, 10, 15,20, 25 or 30 seconds, and at most 120, 90, 60, 55, 50, 45, 40, 35 or 30seconds. The transparent conductive oxide layer should not be heated tomore than 635° F. or 806° F. After the coated articled is heated, it iscooled rapidly to a normal temperature at a particular rate.

The coated article can be flash annealed to increase the sheetresistance. This is done by using a flash lamp to heat a surface of thecoated article. The surface that is heated is the surface on which thetransparent conductive oxide layer resides. The surface is heated to atemperature of above 380° F., at least 435° F. or at least 635° F. forat least 5, 10, 15, 20, 25 or 30 seconds, and at most 120, 90, 60, 50,55, 45, 40, 35 or 30 seconds. The surface should be heated to no morethan 968° F., no more than 878° F., no more than 806° F. or no more than635° F. After the surface is heated, it is cooled to a normaltemperature.

Passing an Eddy current through the transparent conductive oxide (“TCO”)can be done by exposing the transparent conductive oxide layer to achanging magnetic field. For example a magnetic field can be appliedover a substrate that is coated with a TCO. The TCO faces the magneticfield. The Eddy current is passed through the transparent conductiveoxide layer.

Another exemplary method is a method to lower sheet resistance of acoated article. A substrate is provided. The substrate in this methodmay be glass, plastic or metal. Optionally, the substrate is coated withan underlayer. The underlayer can comprise one film, two films, or more.The substrate is coated with a transparent conductive oxide by applyinga transparent conductive oxide over at least a portion of the substrateor underlayer. Optionally, an embedded film is applied within thetransparent conductive oxide layer. This optional step is done byapplying a first portion of the transparent conductive oxide layer,applying the embedded layer over at least a portion of the first portionof the transparent conductive oxide layer, and applied a second portionof the transparent conductive oxide layer over at least a portion of theembedded layer. The coated article is processed with one of thepost-deposition processes described above.

Optionally, the method may further include applying a protective layer,as described herein, over at least a portion of the transparentconductive oxide layer. The protective layer can have two protectivefilms, or three protective films.

By treating an article with a post-deposition process, the sheetresistance of the article decrease to less than 25 ohms per square, lessthan 20 ohms per square; less than 18 ohms per square, less than 16 ohmsper square, or less than 15 ohms per square. This is particularly usefulto reduce the thickness of a TCO. For example, AZO can have a thicknessof less than 400 nm, or 320 nm, and greater than 160 nm. AZO should havea thickness of less than 344 nm and greater than 172 nm. ITO should havea thickness of less than 275 nm or 175 nm; and greater than 95 nm.

One exemplary embodiment is a method of making a coated glass articlewherein a glass substrate is provided. An undercoating is applied overthe glass substrate, preferably by a magnetron sputtered vacuumdeposition or process, some other process that does not use radiant heator the undercoating is applied over the substrate at room temperature.Preferably the undercoating comprises two films wherein the first filmcomprises a zinc oxide and a tin oxide and the second film comprisessilica and titania. A transparent conductive oxide is applied over theundercoating, preferably by a magnetron sputtered vacuum depositionprocess, some other process that does not use radiant heat or thetransparent conductive oxide is applied over the undercoating at roomtemperature. Preferably the transparent conductive oxide is tin-dopedindium oxide. An optional protective layer is applied over thetransparent conductive oxide, preferably by a magnetron sputtered vacuumdeposition or process, some other process that does not use radiant heator the optional protective layer is applied over the transparentconductive oxide at room temperature. The absorption of the transparentconductive oxide is not greater than 0.2, and/or is at least as high as0.05.

In one exemplary embodiment, the article is a refrigerator door.Refrigerator doors would be treated with a post-deposition processsometime prior to assembly, but well after the metal for the exterior ofthe door is coated. Typically, refrigerator doors are heated to allowone to bend the coated article into a shape that will appropriately fitthe door. This heating process would crystallize the transparentconductive oxide, and reduce the sheet resistance.

EXAMPLES

It will be readily appreciated by one of ordinary skill in the art thatmodifications may be made to the invention without departing from theconcepts disclosed in the foregoing description. Accordingly, theparticular embodiments described in detail herein are illustrative onlyand are not limited to the scope of the invention, which is to be giventhe full breadth of the appended claims and any and all equivalentsthereof.

Example 1 (010761)

A glass substrate was coated with an underlayer, and a transparentconductive oxide layer. The underlayer had a first underlayer film and asecond underlayer film. The first underlayer film was zinc stannate overthe glass substrate, and the second underlayer film was a silica-aluminaalloy having about 85 weight percent silica and 15 weight percentalumina over the first underlayer film. The transparent conductive oxidelayer over the second underlayer film was tin-doped indium oxide(“ITO”).

In order to improve the conductivity of the coated article, the entirearticle was placed into a furnace and the temperature of the transparentconductive oxide layer was measured (see FIG. 7).

The following samples were tested to establish the improved conductivityfor each thickness of ITO.

ITO Thickness ITO Surface Temp. Sheet Resistance Sample (nm) (° F.)(Ω/□) 1 96.8 Not flash annealed 68.4 2 96.8 435 23.6 3 96.8 635 24.8 496.8 806 21.8 5 96.8 878 21.2 6 96.8 968 20.2 8 105.2 Not flash annealed67.2 8 105.2 435 23.0 9 105.2 635 23.6 10 105.2 806 21.2 11 105.2 87820.6 12 105.2 968 19.6 13 111.6 Not flash annealed 67.2 14 111.6 43521.8 15 111.6 635 23.6 16 111.6 806 20.6 17 111.6 878 20.0 18 111.6 96819.0 19 114.9 Not flash annealed 67.2 20 114.9 435 21.2 21 114.9 63522.4 22 114.9 806 18.9 23 114.9 878 18.9 24 114.9 968 17.9 25 127.9 Notflash annealed 61.3 26 127.9 435 18.9 27 127.9 635 20.0 28 127.9 80617.7 29 127.9 878 17.1 30 127.9 968 14.9 31 133.1 Not flash annealed60.2 32 133.1 435 17.7 33 133.1 635 19.5 34 133.1 806 17.1 35 133.1 87815.9 36 133.1 968 14.3 37 147.9 Not flash annealed 58.4 38 147.9 43517.7 39 147.9 635 18.9 40 147.9 806 16.5 41 147.9 878 15.3 42 147.9 96813.1 43 160.3 Not flash annealed 56.6 44 160.3 435 16.5 45 160.3 63518.3 46 160.3 806 15.3 47 160.3 878 14.1 48 160.3 968 13.1 49 170.8 Notflash annealed 54.3 50 170.8 435 15.3 51 170.8 635 16.5 52 170.8 80614.1 53 170.8 878 14.1 54 170.8 968 12.0

As can be seen in FIG. 7, post-depositing heating of the ITO, regardlessof the thickness, decreased the sheet resistance from about 55-70Ω/□ toabout 10-25Ω/□. When the ITO thickness was at least than 96.8 nm thick,the sheet resistance was less than 25Ω/□ regardless of the heatingtemperature. When the ITO thickness was at least 109.2, the sheetresistance was less than 20Ω/□ if the ITO surface reached 968° F. Atapproximately 127.9 nm, the ITO had a sheet resistance of less than20Ω/□ when heated to any temperature. The improvements in sheetresistance was unexpected. Similar results were obtained with othertransparent conductive oxides, suggesting that the temperature,regardless of transparent conductive oxide, should be above 380° F., atleast 435° F., or not above 806° F.

As shown in FIG. 8a-c , post deposition heating increased thecrystallinity of the ITO layer. The samples that were tested are listedin Table 2, below.

TABLE 2 Samples for Example 1 Sample Sample ID Description A UncoatedClear Uncoated clear glass B PC-4042 Clear glass coated with ITO at168.7 nm C PC-4042-40 AH PC-4042 after heating D PC-4045 Clear glasscoated with ITO at 141.7 nm E PC-4045-30 AH PC-4045 after heating FPC-4046 Clear glass coated with ITO at 129.4 nm G PC-4046-30 AH PC-4046after heating

By focusing on the minimal surface temperature needed to increase thecrystal formation of the ITO, a tremendous benefit by conserving energyis obtained.

Example 2

A glass substrate was coated with a transparent conductive oxide layer.The transparent conductive oxide was gallium-doped zinc oxide (“GZO”).Several samples with different GZO thicknesses were prepared and thesheet resistance measured for samples to compare the effects ofpost-deposition processing to the sheet resistance of GZO as deposited.The post-deposition process was placing the coated article in a furnace.The sheet resistance of each sample was tested before and after flashannealing, and the results are shown in FIG. 9. The thickness and sheetresistance for the samples test are listed in Table 3, below.

TABLE 3 Samples from Example 2 GZO Thickness Sheet Resistance SheetResistance Sample (nm) (as deposited) (flash annealed) 1 160 84.4 36.6 2320 35.6 12.7 3 400 26.9 9.6 4 480 21.8 7.8 5 640 16.2 5.3 6 800 12.04.2 7 960 7.6 2.7 8 1200 9.9 3.5

As shown in FIG. 9, post-deposition flash annealing of the GZO improvedthe sheet resistance for all of the thicknesses tested. The improvementwas most significant when the GZO was approximately 320-480 nm thick.When the GZO layer was approximately 320 nm thick, the “as-deposited”GZO layer provided a sheet resistance of 35.6 ω/□ whereas afterheat-treatment, the sheet resistance was 12.7Ω/□. This is significantbecause at this thickness, the flash annealing reduced the sheetresistance into an acceptable range whereas without the flash annealing,the sheet resistance was unacceptably high.

A similar result was observed when the GZO was 480 nm thick. The sheetresistance of the “as-deposited” GZO sample was approximately 21.8Ω/□whereas the heat treated sample was 7.8 ω/□.

The difference in sheet resistance is reduced to when at very highthicknesses of GZO. For example, at approximately 950 nm, the“as-deposited” GZO sample had a sheet resistance of approximately 8 ω/□whereas the flash annealed sample had a sheet resistance ofapproximately 5Ω/□. In this case, both samples had adequately low sheetresistance.

Thus, as shown in FIG. 9, for samples with GZO as the transparentconductive oxide, the thicknesses that provide the greatest and mostsignificant difference in sheet resistance is when the GZO layer is atleast 300 nm thick, and at most 500 nm thick.

Heat-treatment reduces the thickness of the transparent conductive oxidelayer needed to reach an acceptable sheet resistance. Without anypost-deposition treatment, the GZO would have to be applied to at least550 nm before the sheet resistance would be less than 20Ω/□. Heatingallows one to apply thinner GZO layers. Not only does this reduce thecost of making an appropriate coated article, but it also reduces theeffect that the GZO has on the optics and color of the coated article.

This was surprising to find, and provided a cost effective approach forimproving sheet resistance of thinner transparent conductive oxidelayers.

Example 3

A glass substrate was coating an aluminum-doped zinc oxide (“AZO”)transparent conductive oxide layer. Several samples with different AZOthicknesses were prepared and the sheet resistance measured for samplesto compare the effects of post-deposition processing to the sheetresistance of AZO as deposited. The post-deposition process involvedplacing the coated article in a furnace. The sheet resistance of eachsample was tested before and after flash annealing, and the results areshown in FIG. 10. The thickness and sheet resistance for the samplestest are listed in Table 4, below.

TABLE 4 Samples from Example 3 AZO Thickness Sheet Resistance SheetResistance Sample (nm) (as deposited) (flash annealed) 1 172 166.0 46.92 344 78.3 19.5 3 430 58.4 14.5 4 516 48.1 12.2 5 688 35.3 8.6 6 86026.6 7.1 7 1032 17.0 3.9

As shown in FIG. 10, post-deposition heating of the AZO improved thesheet resistance for all of the thicknesses tested. The improvement wasmost significant when the AZO was approximately 344 to 860 nm thick.When the AZO layer was 344 nm thick, the “as-deposited” AZO layerprovided a sheet resistance of approximately 78.3 ω/□ whereas afterheat-treatment, the sheet resistance was 19.5Ω/□. This is significantbecause at this thickness, heating reduced the sheet resistance into anacceptable range whereas without heating, the sheet resistance wasunacceptably high.

A similar result was observed when the AZO was 860 nm thick. The sheetresistance of the “as-deposited” AZO sample was approximately 26.6Ω/□whereas the heat-treated sample was approximately 7.1 ω/□.

The difference in sheet resistance is reduced to when at very highthicknesses of AZO. For example, at approximately 1050 nm, the“as-deposited” AZO sample had a sheet resistance of approximately 17.0ω/□ whereas the heat-treated sample had a sheet resistance of 3.9Ω/□. Inthis case, both samples had adequately low sheet resistance.

Thus, as shown in FIG. 10, for samples with AZO as the transparentconductive oxide, the thicknesses that provide the greatest and mostsignificant difference in sheet resistance is when the AZO layer is atleast 344 nm thick, and at most 860 nm thick.

Heating also reduces the thickness of the transparent conductive oxidelayer needed to reach an acceptable sheet resistance. Without anypost-deposition treatment, the AZO would have to be applied to at least1032 nm before the sheet resistance would be less than 20Ω/□. Heatingallows one to apply thinner AZO layers. Not only does this reduce thecost of making an appropriate coated article, but it also reduces theeffect that the AZO has on the optics and color of the coated article.

This was surprising to find, and provided a cost effective approach forimproving sheet resistance of thinner transparent conductive oxidelayers.

Example 4

Using FILM STAR, various underlayer thicknesses were tested to determinewhich thicknesses provided an acceptable or neutral color. A glasssubstrate was used having an underlayer, and a transparent conductiveoxide. The underlayer had a first film and a second film. The firstunderlayer film was zinc stannate over the glass substrate, and thesecond underlayer film was a silica-alumina alloy having about 85 weightpercent silica and 15 weight percent alumina over the first underlayerfilm. The transparent conductive oxide layer over the second underlayerfilm was a 170 nm thick tin-doped indium oxide (“ITO”) layer.

First, a desired sheet resistance was determined. For this example, thedesired sheet resistance was approximately between 10Ω/□ and 15Ω/□. Toachieve this sheet resistance, it was determined that the transparentconductive oxide layer should be approximately 170 nm thick.

Using FILM STAR, the material and thickness of the glass and thetransparent conductive oxide layer was entered. Next, the material forthe first underlayer film and the second underlayer film weredetermined. For this example, the first underlayer film material waszinc stannate and the second underlayer film material was asilica-alumina alloy having 85 weight percent silica and 15 weightpercent alumina. The following coatings were analyzed by FILM STAR (seeTable 5 and FIG. 11). The thicknesses of the first underlayer firstranged from 8 nm to 17 nm in the samples, and the thicknesses of thesecond underlayer film ranged from 27 nm and 35 nm.

TABLE 5 Samples from Example 4 ZnSnO_(x) SiAlO_(x) ITO Color Samplethickness (nm) thickness (nm) thickness (nm) (a*, b*) 1 13 27 170 (−3.5,1.6)  2 13 28 170 (−2.9, 1.1)  3 13 29 170 (−2.3, 0.5)  4 13 30 170(−1.8, −0.1) 5 13 31 170 (−1.2, −0.8) 6 13 32 170 (−0.7, −1.5) 7 13 33170 (−0.1, −2.2) 8 13 34 170  (0.5, −2.9) 9 13 35 170    (1, −3.6) 10 831 170 (−5.3, −4)  11 9 31 170 (−4.6, −3.2) 12 10 31 170 (−3.8, −2.5) 1311 31 170  (−3, −1.8) 14 12 31 170 (−2.1, −1.3) 15 13 31 170 (−1.2,−0.8) 16 14 31 170 (−0.3, −0.4) 17 15 31 170  (0.8, −0.2) 18 16 31 170(1.8, 0)  19 17 31 170 (2.9, 0) 

As shown in FIG. 11, a neutral color of a*, b* of −1, −1 was obtainedwhen the first underlayer film was 13 nm thick and the second underlayerfilm was 31 nm thick. Acceptable colors wherein the a* was between −3and 1, and the b* was between −3 and 1 was obtained when the firstunderlayer film was between 11 nm and 15 nm thick, and the secondunderlayer film was between 29 nm and 33.5 nm thick.

Example 5

Using FILM STAR, varying thicknesses of the transparent conductive oxidelayer was tested to determine the appropriate thicknesses for theunderlayer. In this example, the FILM STAR parameters included a glasssubstrate coated with an underlayer having a first underlayer film and asecond underlayer film. The first underlayer film was zinc stannate andthe second underlayer film was silica. The transparent conductive oxidelayer over the second underlayer film was tin-doped indium oxide(“ITO”). A silica protective layer was over the ITO layer. Table 6 andFIG. 12 show the samples that were tested. Table 6 shows the values thatwere inputted into FILM STAR for the ITO layer and the SiO₂ layer. Theoutput provided thicknesses for the two underlayer films that wouldprovide a −1, −1 (a*, b*) color.

TABLE 6 Samples for Example 5 Sample ITO SiO₂ 1 225 nm 30 nm 2 205 nm 30nm 3 200 nm 30 nm 4 190 nm 30 nm 5 180 nm 30 nm 6 175 nm 30 nm 7 175 nm45 nm 8 180 nm 45 nm 9 190 nm 45 nm 10 200 nm 45 nm 11 205 nm 45 nm 12225 nm 45 nm

These samples show that when the first underlayer film should be atleast 10 nm thick and at most 15 nm thick and the second underlayer filmshould be at least 28 nm thick and at most 36 nm thick to achieve acolor of about −1, −1 (a*, b*) when the transparent conductive oxidelayer is between 175 nm and 225 nm thick and the protective coating is30 nm thick. The samples also show that the first underlayer film shouldbe at least 11 nm thick and at most 14 nm thick, and the secondunderlayer film should be at least 32 nm thick and at most 38 nm thickto achieve an appropriate color when the transparent conductive oxidelayer is between 175 nm and 225 nm thick, and the protective layer is 45nm thick.

FIG. 12 shows the ideal thicknesses that will result in a −1, −1 color.While a −1, −1 is preferred other colors are acceptable, such as colorsencircled in FIG. 11 (i.e. a* between −3 and 1, and b* between −3 and1).

Example 6

The effect of an embedded film was tested at various depths andthicknesses and compared to a transparent conductive oxide layer withoutan embedded layer. A glass substrate was coated with a bottomtransparent conductive oxide film. The bottom transparent conductiveoxide film was made from tin-doped indium oxide (“ITO”), and was 120 nm,180 nm or 240 nm thick. An embedded film was applied over the bottomtransparent conductive oxide layer. The embedded film was either 15 nmor 30 nm thick, and was a zinc stannate film. A top transparentconductive oxide film was applied over the embedded film. The toptransparent conductive oxide film was ITO, and was 240 nm, 180 nm or 120nm thick. The combined thickness of the bottom and top transparentconductive oxide films was 360 nm. For a control, ITO oxide was appliedover the substrate at a thickness of 360 nm, and it did not contain anembedded film. The sheet resistance and transmission at 550 nm wasmeasured for the samples. The samples are listed in Table 7, below, andin FIG. 13.

TABLE 7 Samples from Example 6 Sample Bottom ITO Zn₂SnO₄ Top ITO A 120nm 15 nm 240 nm B 120 nm 30 nm 240 nm C 180 nm 15 nm 180 nm D 180 nm 30nm 180 nm E 240 nm 15 nm 240 nm F 240 nm 30 nm 240 nm G 360 nm N/A N/A

As shown in FIG. 13a , experimental samples A-F had at least a 35%improvement in sheet resistance as compared to the control, sample G.Samples A and B had at least a 40% improvement in sheet resistance ascompared to sample G. Samples C and D had at least a 35% improvement insheet resistance as compared to sample G. Samples E and F had at least a37% improvement in sheet resistance as compared to sample G.

Based on this data, the embedded film, regardless of its position orthickness, surprisingly and significantly decrease the sheet resistanceof the transparent conductive oxide layer.

As shown in FIG. 13b , samples E and F provided the greatest increase intransmission. A smaller improvement was seen in samples A and B. Thus,by having a difference in thickness between the top and bottomtransparent conductive oxide layer, one can increase the amount of lighttransmission. Furthermore, it was surprising to find that if the toptransparent conductive oxide layer is thinner than the bottom one,thereby the embedded layer is positioned closer to the surface of thetop of the transparent conductive oxide layer rather than the bottom ofthe transparent conductive oxide layer, there is a much larger increasein transmission. By contrast, if the top and bottom transparentconductive oxide layer are approximately equal, there is an unexpecteddecrease in light transmission.

FIG. 13c shows that the embedded film also impacts the crystallinity ofthe transparent conductive oxide. By having an embedded film, one cansee from this XRD data that crystallinity is unexpectedly improved.

Example 7

In this example, various protective layers were examined. The protectivelayers were placed over a glass substrate. The coated article didincluded aluminum-doped zinc oxide transparent conductive oxide betweenthe substrate and the protective layer. One would not expect that theunderlayer, functional layer or transparent conductive oxide layer wouldnot impact the results observed.

The glass substrate was different protective layers. Samples 1-3 had aprotective layer that comprised a single film. A list of these samplesis provided in Table 8.

TABLE 8 Protective-Layer Stack Sample Protective Layer 1 None 2 SiAlO 3TiAlO 4 ZrO₂

Samples 5-11 had a protective layer comprising a first protective filmand a second protective film over the first protective film. A list ofthese samples is provided in Table 9. The first film is closer to thesubstrate than the second film, and the second film is the outer mostfilm.

TABLE 9 Samples Protective Layer with Two Films Sample 1^(st) film2^(nd) film 5 TiAlO SiAlO 6 SiAlO TiAlO 7 SnZnO TiAlO 8 SnZnO SiAlO 9TiAlO ZrO₂ 10 SiAlO ZrO₂ 11 SnZnO ZrO₂

Samples 12-15 had a protective layer comprising three films. A list ofthese samples is provided in Table 10. The first film is closer to thesubstrate than the second or third film. For the sake of consistencywith the other figures and description above, the second protective filmis the outer most film, and the third protective film was positionedbetween the first film and the third film.

TABLE 10 Sample Protective Layers with Three Films Sample 1^(st) film3^(rd) film 2^(nd) film 12 SnZnO TiAlO SiAlO 13 SnZnO SiAlO TiAlO 14SnZnO TiAlO ZrO₂ 15 SnZnO SiAlO ZrO₂ 16 TiAlO SiAlO ZrO₂ 17 SiAlO TiAlOZrO₂ 18 ZrO₂ TiAlO SiAlO 19 ZrO₂ SiAlO TiAlO 20 SiAlO ZrO₂ TiAlO 21TiAlO ZrO₂ SiAlO

The durability of these samples was tested using ASTM ClevelandCondensation test. As shown in FIGS. 14 and 15, the protective film thathad TiAlO as the outer most layer performed the best. These figures showthe dEcmc for samples 1-15 listed in Tables 8-10.

Specifically, FIG. 14 shows that samples that had two or threeprotective films wherein the outer most film was TiAlO had unexpectedlybetter durability. Specifically, samples 6 (SiAlO//TiAlO), sample 7(SnZn/TiA10), and sample 13 (SnZn/SiAlO//TiAlO). FIG. 15 furtherdemonstrates that protective layers having titania and alumina as theouter most layer provided unexpected greater durability. FIG. 15, sample(ZrO₂/SiAlO/TiAlO) and sample 20 (SiAlO/ZrO₂/TiAlO) shows unexpectedlybetter durability as compared to the other three-film protective layersamples (samples 16, 17, 18, and 21).

This data shows an unexpected result that a titania-alumina outer-mostprotective film provides greatly improved durability.

Example 8

Samples with transparent conductive oxides sputtered in variousatmospheres were tested. As shown in FIGS. 16-20, glass substrates werecoated with either indium-doped tin oxide (“ITO”) or aluminum-doped zincoxide (“AZO”) via magnetron sputter vacuum deposition (“MSVD”) method.The ITO samples were sputtered in an atmosphere that contained 0%, 0.5%,1%, 1.5% or 2% oxygen and thereafter heat-treated, and the AZO sampleswere sputtered in an atmosphere that contained 0%, 1%, 2%, 3%, 4%, 5% or6% oxygen and thereafter heat treated. The remainder of the atmospherewas argon. The ITO samples had an ITO thickness of either 225 nm, 175 nmor 150 nm, and the AZO samples had a thickness of 300 nm to 350 nm ofAZO applied onto the substrate. The samples were tested to determinetheir emissivity, absorbance and/or sheet resistance. (Emissivity is ameasure of conductivity.) These samples were heat treated by placing thecoated article into a furnace for a period of time so that thetransparent conductive oxide surface of the sample to reached at least435° F. for about 30 seconds.

When coating a transparent article with a transparent conductive oxide,one wants a low absorbance and low sheet resistance (which correspondsto emissivity) article. FIG. 16 shows that as oxygen is added to theatmosphere, the absorption decreases. However, as shown by FIG. 17, theemissivity/sheet resistance of the article is highest when there is 0%oxygen in the atmosphere. Using FIGS. 16 and 17, the ideal balancebetween absorption and emissivity is obtained when the sputteringatmosphere has between 0.75% and 1.25% oxygen in the atmosphere. As FIG.17 shows, the sheet resistance of a heat-treated article coated with ITOis lower than non-heated articles coated with an ITO if the atmospherehas less than 2.0% oxygen. There is a significant increase in the sheetresistance when the atmosphere is 1.5% oxygen. Extrapolating from thisdata, it was concluded that the atmosphere in the coating chamber shouldbe no more than 1.5% oxygen, preferably no more than 1.25%. In order toobtain some decrease absorption for ITO coated article, the atmosphereshould contain at least 0.5% oxygen, preferably at least 0.75% oxygen.

Example 9

A glass substrate was coated with an aluminum-doped zinc oxide layer bya magnetron sputter vacuum deposition (“MSVD”) process. The target was aceramic aluminum-doped zinc oxide, which contains a certain amount ofoxygen in it. When using a MSVD process to deposit a material such as atransparent conductive oxide, the process causes the ceramic rawmaterials to disassociate, possibly causing some of the oxygen toescape. In order to ensure that the material deposited is oxidized,often oxygen is supplied to the coating chamber together with an inertgas. In this example, the AZO was deposited by MSVD in a coating chamberthat had the oxygen content supplied to the chamber that was either 0%,1%, 2%, 3%, 4%, 5% or 6%. The remainder of the atmosphere supplied tothe coating chamber was argon, however, any inert gas could be used. Thenormalized absorption of the coating was determined. As shown in FIG.18, the normalized absorption at 550 nm was best when 0% oxygen wassupplied to the coating chamber. It was acceptable when 1% oxygen wassupplied to the coating chamber. Based on the data shown in FIG. 18, onewould extrapolate that less than 0.5% oxygen in the coating chamberprovides significantly better absorption than when 1% oxygen is used.

As shown in FIG. 19, the normalized absorption has a steep decline from0% oxygen to 1% oxygen, and a minimal decline from 1% oxygen to 2%oxygen. This data further supports the conclusion that, byextrapolation, one would conclude that less than 1% oxygen, less than0.5% oxygen, or less than 0.25% oxygen, or less than 0.1% oxygen, or 0%oxygen supplied to the coating chamber provides the best absorption.

Example 10

One problem with post-deposition heating of a coated article is theamount of energy wasted. As discussed above, post deposition heating ofa transparent conductive oxide (“TCO”) layer provides improvedperformance at smaller thicknesses. Placing a coated article into afurnace that heats the entire article wastes energy beyond thetemperature necessary to crystalize the TCO layer. In order to determinethe surface temperature needed to improve the performance of atransparent conductive oxide layer, a glass substrate was coated withindium-doped tin oxide at 115 nm or 171 nm thick. The samples had thesurface of the ITO layer heated to temperatures listed in Tables 11 and12. For the purpose of this experiment, the surfaces were heated byplacing the entire coated article into a furnace, however, a flash lampcould be used as an alternative.

After the post-deposition heating of the surface, the sheet resistanceof each sample was measured (see FIG. 21, and Tables 11 and 12). Theresults show that at approximately 435° F., the layer reaches its lowestsheet resistance. Additionally heating the surface does not provide anyadditional reduction in sheet resistance. Therefore, in order to reducethe sheet resistance of a transparent conductive oxide layer, the postdeposition heating should heat the surface of the transparent conductiveoxide layer to above 380° F., at least 435° F., between 435° F. and 806°F., between 435° F. and 635° F., or to 435° F.

TABLE 11 115 nm Thick ITO Samples of Example 10 Max. Surface SheetResistance Temperature (° F.) (Ω/□) 72 200 69.7 300 67 317 68.9 350 65.3380 62.6 435 21.2 635 22.4 806 18.9 878 18.9 968 17.9

TABLE 12 171 nm Thick ITO Samples of Example 10 Max. Surface SheetResistance Temperature (° F.) (Ω/□) Room Temperature 200 52.3 300 52.3317 43.9 350 49 380 43.5 435 15.3 635 16.5 806 14.1 878 14.1 968 12

The invention is further described in the following numbered clauses.

Clause 1: A coated article comprising a substrate, an underlayer oversaid substrate, the underlayer comprising a first underlayer filmwherein the first underlayer film comprises a high refractive indexmaterial, and a second underlayer film over the first layer wherein thesecond layer comprises a low refractive index material, and atransparent conductive oxide layer over the underlayer.

Clause 2: The coated article according to claim 1, wherein the highrefractive index material comprises zinc oxide and tin oxide.

Clause 3: The coated article of clauses 1 or 2, wherein the lowrefractive index material comprises silica and alumina.

Clause 4: The coated article of any of the clauses 1 to 3, wherein thetransparent conductive film comprises tin-doped indium oxide.

Clause 5: The coated of any of the clauses 1 to 4, wherein thetransparent conductive oxide layer has a thickness of at least 75 nm, atparticularly at least 90 nm, more particularly at least 100 nm, moreparticularly at least 125 nm, more particularly at least 150 nm, or moreparticularly at least 175 nm.

Clause 6: The coated article of any of the clauses 1 to 5, wherein thetransparent conductive oxide layer has a thickness of at most 350 nm,particularly at most 300 nm, particularly at most 275 nm, particularlyat most 250 nm, more particularly at most 225 nm.

Clause 7: The coated article of any of the clauses 1 to 6 wherein thecoated article has a sheet resistance in the range of 5 to 25 ohms persquare, particularly 5 to 20 ohms per square, more particularly 8 to 18ohms per square, more particularly 5 to 15 ohms per square

Clause 8: The coated article of any of the clauses 1 to 7, wherein thefirst underlayer film has a first underlayer thickness and the secondunderlayer film has a second underlayer thickness to provide the coatedarticle with a color having an a* of at least −9 and at most 1,particularly at least −4 and at most 0, more particularly at least −3and at most 1, more particularly at least −1.5 and at most −0.5, moreparticularly −1; and a b* of at least −9 and at most 1, particularly atleast −4 and at most 0, more particularly at least −3 and at most 1,more particularly at least −1.5 and at most −0.5, more particularly −1.

Clause 9: The coated article of any of the clauses 1 to 8, wherein thehigh refractive index material comprises zinc oxide.

Clause 10: The coated article of any of the clauses 1 to 9 furthercomprising a protective layer over the transparent conductive oxidelayer wherein the protective layer comprises a first protective film anda second protective film over at least a portion of the first protectivefilm, wherein the second protective film is an outermost film and thesecond protective film comprises titania and alumina.

Clause 11: The coated article of clause 10 wherein the first protectivefilm comprises titania, alumina, zinc oxide, tin oxide, zirconia,silica, or mixtures thereof. Optionally, the first protective film doesnot comprise a mixture of titania and alumina.

Clause 12: The coated article of the clauses 9 or 10 wherein the secondprotective film comprises 35 to 65 weight percent titania; particularly45 to 55 weight percent titania; more particularly 50 weight percenttitania.

Clause 13: The coated article of any of the clauses 10 to 12 wherein thesecond protective film comprises 65 to 35 weight percent alumina,particularly 55 to 45 weight percent alumina, more particularly 50weight percent alumina.

Clause 14: The coated article of any of the clauses 10 to 13 furthercomprising a third protective film over at least a portion of the firstprotective film and positioned between the first protective film and thesecond protective film, or between the first protective film and thefunctional coating wherein the third protective film comprises titania,alumina, zinc oxide, tin oxide, zirconia, silica, or mixtures thereof.Optionally, the third protective film does not comprise a mixture oftitania and alumina.

Clause 15: A method of adjusting a color of coated substrate comprisingproviding a substrate; identifying a transparent conductive oxide and atransparent conductive oxide layer thickness for a transparentconductive oxide layer that will provide a sheet resistance of at least5Ω/□ and no more than 25Ω/□ (particularly no more than 20 ω/□, moreparticularly no more than 18Ω/□, identifying a first underlayer materialand a first underlayer thickness for a first underlayer film, and asecond underlayer material and a second underlayer thickness that willprovide the coated substrate having the transparent conductive oxide atthe transparent conductive layer thickness a color having an a* between−9 and 1, particularly between −4 and 0, more particularly between −3and 1, more particularly between −1.5 and −0.5; and a b* of between −9and 1, particularly between −4 and 0, more particularly between −3 and1, more particularly between −1.5 and −0.5, applying the firstunderlayer film having the first underlayer thickness is applied over atleast a portion of the substrate; applying the second underlayer filmhaving the second underlayer thickness over at least a portion of thefirst underlayer film; and applying the transparent conductive oxidelayer over the transparent conductive oxide at the transparentconductive layer thickness over at least a portion of the underlayer.

Clause 16: The method of clause 15 wherein the transparent conductiveoxide is tin-doped indium oxide.

Clause 17: The method of clause 15 or 16 wherein the transparentconductive layer thickness is at least 125 nm (particularly at least 150nm, more particularly at least 175 nm) and no more than 950 nm(particularly 500 nm, more particularly 350 nm, more particularly 225nm).

Clause 18: The method of any of the clauses 15 to 17 wherein the firstunderlayer material comprises zinc oxide and tin oxide.

Clause 19: The method of any of the clauses 15 to 18 wherein the firstunderlayer thickness is at least 11 nm and no more than 15 nm.

Clause 20: The method of any of the clauses 15 to 19 wherein the secondunderlayer material comprises silica and alumina.

Clause 21: The method of any of the clauses 15 to 20, wherein the secondunderlayer thickness is at least 29 nm and no more than 34 nm.

Clause 22: The method of any of the clauses 15 to 21 further comprisingapplying a protective layer over a portion of the transparent conductiveoxide layer wherein the protective layer comprises a first protectivefilm and a second protective film over at least a portion of the firstprotective film, wherein the second protective film is an outermost filmand the second protective film comprises titania and alumina.

Clause 23: The method of clause 22 wherein the first protective filmcomprises titania, alumina, zinc oxide, tin oxide, zirconia, silica, ormixtures thereof. Optionally, the first protective film does notcomprise a mixture of titania and alumina.

Clause 24: The method of clauses 22 or 23 wherein the second protectivefilm comprises 35 to 65 weight percent titania; particularly 45 to 55weight percent titania; more particularly 50 weight percent titania.

Clause 25: The method of any of the clauses 22 to 25 wherein the secondprotective film comprises 65 to 35 weight percent alumina, particularly55 to 45 weight percent alumina, more particularly 50 weight percentalumina.

Clause 26: The method of any of the clauses 22 to 25 further comprisinga third protective film over at least a portion of the first protectivefilm and positioned between the first protective film and the secondprotective film, or between the first protective film and the functionalcoating wherein the third protective film comprises titania, alumina,zinc oxide, tin oxide, zirconia, silica, or mixtures thereof.Optionally, the third protective film does not comprise a mixture oftitania and alumina.

Clause 27: A coated article comprising a substrate, an underlayer overat least a portion of the substrate, and a transparent conductive oxidelayer over at least a portion of the underlayer. The underlayer has afirst underlayer film and an optional second underlayer film. The firstunderlayer film comprises a first high refractive index material. Theoptional second underlayer film comprises a low refractive indexmaterial. The first high refractive index material has a refractiveindex that is higher than the low refractive index material. Thetransparent conductive oxide layer has an embedded film embedded withinthe transparent conductive oxide layer. The embedded film comprises asecond high refractive index material. The second high refractive indexmaterial has a refractive index that is higher than the low refractiveindex material.

Clause 28: The coated article according to clause 27 wherein theembedded film has a thickness of 5 nm to 50 nm, particularly 10 nm to 40nm, more particularly 15 nm to 30 nm.

Clause 29: The coated article according to clause 27 or 29 wherein thesecond high refractive index material comprises tin oxide and zincoxide.

Clause 30: The coated article according to any of the clauses 27 to 29wherein the embedded film is positioned closer to a top of thetransparent conductive oxide layer.

Clause 31: The coated article according to any of the clauses 27 to 29wherein the embedded film is positioned closer to a bottom of thetransparent conductive oxide layer.

Clause 32: The coated article according to any of the clauses 27 to 29wherein the embedded film is positioned at approximately a middle of thetransparent conductive oxide layer.

Clause 33: The coated article according to any of the clauses 27 to 32wherein the transparent conductive oxide layer is selected from thegroup consisting of gallium-doped zinc oxide (“GZO”), aluminum-dopedzinc oxide (“AZO”), indium-doped zinc oxide (“IZO”) magnesium-doped zincoxide (“MZO”), or tin-doped indium oxide (“ITO”), particularly GZO, AZOand ITO, more particularly ITO.

Clause 34: The coated article according any of the clauses 27 to 33,wherein the high refractive index material comprises zinc oxide and tinoxide.

Clause 35: The coated article of any of the clauses 27 to 34, whereinthe low refractive index material comprises silica and alumina.

Clause 36: The coated article of any of the clauses 27 to 35, whereinthe transparent conductive oxide layer has a thickness of at least 75nm, more particularly at least 90 nm, more particularly at least 100 nm,more particularly at least 125 nm, more particularly at least 150 nm,more particularly at least 175 nm, or more particularly at least 320 nm.

Clause 37: The coated article of any of the clauses 27 to 34, whereinthe transparent conductive oxide layer has a thickness of at most 950nm, particularly at most 550 nm, more particularly at most 480 nm, moreparticularly at most 350 nm, more particularly at most 300 nm, moreparticularly at most 275 nm, more particularly at most 250 nm, moreparticularly at most 225 nm.

Clause 38: The coated article of any of the clauses 27 to 37 wherein thecoated article has a sheet resistance in the range of 5 to 20 ohms persquare, particularly 8 to 18 ohms per square, more particularly 5 to 15ohms per square.

Clause 39: The coated article of any of the clauses 27 to 38, whereinthe first underlayer film has a first underlayer thickness, the secondunderlayer film has a second underlayer thickness and the embedded filmhas an embedded film thickness to provide the coated article with acolor having an a* of at least −9 and at most 1, particularly at least−4 and at most 0, more particularly at least −3 and at most 1, moreparticularly at least −1.5 and at most −0.5, more particularly −1; and ab* of at least −9 and at most 1, particularly at least −4 and at most 0,more particularly at least −3 and at most 1, more particularly at least−1.5 and at most −0.5, more particularly −1.

Clause 40: The coated article of clause 39 wherein the first underlayerfilm thickness is between 11 nm and 15 nm, and/or the second underlayerfilm thickness is between 29 nm and 34 nm.

Clause 41: The coated article of any of the clauses 27 to 40 furthercomprising a protective layer over the transparent conductive oxidelayer wherein the protective layer comprises a first protective film anda second protective film over at least a portion of the first protectivefilm, wherein the second protective film is an outermost film and thesecond protective film comprises titania and alumina.

Clause 42: The coated article of clause 41 wherein the first protectivefilm comprises titania, alumina, zinc oxide, tin oxide, zirconia,silica, or mixtures thereof. Optionally, the first protective film doesnot comprise a mixture of titania and alumina.

Clause 43: The coated article of clause 41 or 42 wherein the secondprotective film comprises 35 to 65 weight percent titania; particularly45 to 55 weight percent titania; more particularly 50 weight percenttitania.

Clause 44: The coated article of any of the clauses 40 to 43 wherein thesecond protective film comprises 65 to 35 weight percent alumina,particularly 55 to 45 weight percent alumina, more particularly 50weight percent alumina.

Clause 45: The coated article of any of the clauses 40 to 44 furthercomprising a third protective film over at least a portion of the firstprotective film and positioned between the first protective film and thesecond protective film, or between the first protective film and thefunctional coating wherein the third protective film comprises titania,alumina, zinc oxide, tin oxide, zirconia, silica, or mixtures thereof.Optionally, the third protective film does not comprise a mixture oftitania and alumina.

Clause 46: A method of adjusting a color of a coated article. The methodincludes applying a first underlayer film over at least a portion of asubstrate. The first underlayer film comprises a first high refractiveindex material. Optionally, a second underlayer film comprises a lowrefractive index material applied over at least a portion of the firstunderlayer film. The first high refractive index material has arefractive index that is higher than the low refractive index material.A first transparent conductive oxide film is applied over at least aportion of the first underlayer film or the optional second underlayerfilm. An embedded film is applied over at least a portion of the firsttransparent conductive oxide layer. The embedded film comprises a secondhigh refractive index material. The second high refractive indexmaterial has a refractive index that is higher than the low refractiveindex material. A second transparent conductive oxide film is appliedover at least a portion of the embedded film.

Clause 47: The method according to clause 46 wherein the embedded filmhas thickness of 5 nm to 50 nm, particularly 10 nm to 40 nm, moreparticularly 15 nm to 30 nm.

Clause 48: The method according to clause 46 or 47 wherein the secondhigh refractive index material comprises tin oxide and zinc oxide.

Clause 49: The method according to any of the clauses 46 to 47 whereinthe embedded film is positioned closer to a top of the transparentconductive oxide layer.

Clause 50: The method according to any of the clauses 46 to 47 whereinthe embedded film is positioned closer to a bottom of the transparentconductive oxide layer.

Clause 51: The method according to any of the clauses 46 to 47 whereinthe embedded film is positioned at approximately a middle of thetransparent conductive oxide layer.

Clause 52: The method according to any of the clauses 46 to 51 whereinthe first transparent conductive oxide film and/or the secondtransparent conductive oxide film is selected from the group consistingof gallium-doped zinc oxide (“GZO”), aluminum-doped zinc oxide (“AZO”),indium-doped zinc oxide (“IZO”) magnesium-doped zinc oxide (“MZO”), ortin-doped indium oxide (“ITO”), particularly GZO, AZO and ITO, moreparticularly ITO.

Clause 53: The method according any of the clauses 46 to 52, wherein thehigh refractive index material comprises zinc oxide and tin oxide.

Clause 54: The method of any of the clauses 46 to 53, wherein the lowrefractive index material comprises silica and alumina.

Clause 55: The method of any of the clauses 46 to 55, wherein the firsttransparent conductive oxide layer and/or the second transparentconductive oxide layer has a thickness of at least 80 nm, orparticularly at least 120 nm, more particularly at least 180 nm, moreparticularly at least 240 nm or more particularly at least 360 nm.

Clause 56: The method of any of the clauses 46 to 55, wherein the firsttransparent conductive oxide layer and/or the second transparentconductive oxide layer has a thickness of at most 400 nm, particularlyat most 360 nm, more particularly at most 240 nm, more particularly atmost 180 nm, more particularly at most 120 nm or more particularly atmost 80 nm.

Clause 57: The method of any of the clauses 46 to 56 wherein the coatedarticle has a sheet resistance in the range of 5 to 25 ohms per square,particularly 5 to 20 ohms per square, more particularly 5 to 18 ohms persquare.

Clause 58: The method of any of the clauses 46 to 57, wherein the firstunderlayer film has a first underlayer thickness, the second underlayerfilm has a second underlayer thickness and the embedded film has anembedded film thickness to provide the coated article with a colorhaving an a* of at least −9 and at most 1, particularly at least −4 andat most 0, more particularly at least −3 and at most 1, moreparticularly at least −1.5 and at most −0.5, more particularly −1; and ab* of at least −9 and at most 1, particularly at least −4 and at most 0,more particularly at least −3 and at most 1, more particularly at least−1.5 and at most −0.5, more particularly −1.

Clause 59: The method of any of the clauses 46 to 58 wherein the firstunderlayer film thickness is between 11 nm and 15 nm, and/or the secondunderlayer film thickness is between 29 nm and 34 nm.

Clause 60: The method of any of the clauses 46 to 59 further comprisingapplying a protective layer over the transparent conductive oxide layerwherein the protective layer comprises a first protective film and asecond protective film over at least a portion of the first protectivefilm, wherein the second protective film is an outermost film and thesecond protective film comprises titania and alumina.

Clause 61: The method of clause 60 wherein the first protective filmcomprises titania, alumina, zinc oxide, tin oxide, zirconia, silica, ormixtures thereof. Optionally, the first protective film does notcomprise a mixture of titania and alumina.

Clause 62: The method of clause 60 or 61 wherein the second protectivefilm comprises 35 to 65 weight percent titania; particularly 45 to 55weight percent titania; more particularly 50 weight percent titania.

Clause 63: The method of any of the clauses 60 to 62 wherein the secondprotective film comprises 65 to 35 weight percent alumina, particularly55 to 45 weight percent alumina, more particularly 50 weight percentalumina.

Clause 64: The method of any of the clauses 60 to 63 further comprisinga third protective film over at least a portion of the first protectivefilm and positioned between the first protective film and the secondprotective film, or between the first protective film and the functionalcoating wherein the third protective film comprises titania, alumina,zinc oxide, tin oxide, zirconia, silica, or mixtures thereof.Optionally, the third protective film does not comprise a mixture oftitania and alumina.

Clause 65: The method of any of the clauses 47 to 64 wherein the firsttransparent conductive oxide film and the second transparent conductiveoxide film contain an identical metal oxide.

Clause 66: A coated article comprising a substrate, an underlayer overat least a portion of the substrate. The underlayer has a firstunderlayer film and a second underlayer film. The first underlayer filmcomprises a first high refractive index material. The second underlayerfilm comprises a low refractive index material. The first highrefractive index material has refractive index that is higher than thelow refractive index material. A first transparent conductive oxide filmis over at least a portion of the second underlayer film. An embeddedfilm is over at least a portion of the first transparent conductiveoxide film. The embedded film comprises a second high refractive indexmaterial. The second high refractive index material has refractive indexthat is higher than the low refractive index material. A secondtransparent conductive oxide film is over at least a portion of theembedded film.

Clause 67: the coated article according to clause 66 wherein theembedded film has thickness of 5 nm to 50 nm, particularly 10 nm to 40nm, more particularly 15 nm to 30 nm.

Clause 68: The coated article according to clause 66 or 67 wherein thesecond high refractive index material comprises tin oxide and zincoxide.

Clause 69: The coated article according to any of the clauses 66 to 68wherein the first transparent conductive oxide film is thicker than thesecond transparent conductive oxide film.

Clause 70: The coated article according to any of the clauses 66 to 68wherein the first transparent conductive oxide film is thinner than thesecond transparent conductive oxide film.

Clause 71: The coated article according to any of the clauses 66 to 68wherein the first transparent conductive oxide film is approximately thesame thickness as the second transparent conductive oxide film.

Clause 72: The coated article according to any of the clauses 66 to 71wherein the first transparent conductive oxide film and/or the secondtransparent conductive oxide film is selected from the group consistingof gallium-doped zinc oxide (“GZO”), aluminum-doped zinc oxide (“AZO”),indium-doped zinc oxide (“IZO”) magnesium-doped zinc oxide (“MZO”), ortin-doped indium oxide (“ITO”), particularly GZO, AZO and ITO, moreparticularly ITO.

Clause 73: The coated article according any of the clauses 66 to 72,wherein the high refractive index material comprises zinc oxide and tinoxide.

Clause 74: The coated article of any of the clauses 66 to 73, whereinthe low refractive index material comprises silica and alumina.

Clause 75: The coated article of any of the clauses 66 to 74, whereinthe transparent conductive oxide layer has a thickness of at most 950nm, particularly at most 550 nm, more particularly at most 360 nm.

Clause 76: The coated article of any of the clauses 66 to 75 wherein thecoated article has a sheet resistance in the range of 5 to 20 ohms persquare, particularly 8 to 18 ohms per square, more particularly 5 to 15ohms per square.

Clause 77: The coated article of any of the clauses 66 to 80, whereinthe first underlayer film has a first underlayer thickness, the secondunderlayer film has a second underlayer thickness and the embedded filmhas an embedded film thickness to provide the coated article with acolor having an a* of at least −9 and at most 1, particularly at least−4 and at most 0, more particularly at least −3 and at most 1, moreparticularly at least −1.5 and at most −0.5, more particularly −1; and ab* of at least −9 and at most 1, particularly at least −4 and at most 0,more particularly at least −3 and at most 1, more particularly at least−1.5 and at most −0.5, more particularly −1.

Clause 78: The coated article of any of the clauses 76 to 77 wherein thefirst underlayer film thickness is between 11 nm and 15 nm, and/or thesecond underlayer film thickness is between 29 nm and 34 nm.

Clause 79: The coated article of any of the clauses 66 to 78 furthercomprising a protective layer over the transparent conductive oxidelayer wherein the protective layer comprises a first protective film anda second protective film over at least a portion of the first protectivefilm, wherein the second protective film is an outermost film and thesecond protective film comprises titania and alumina.

Clause 80: The coated article of clause 79 wherein the first protectivefilm comprises titania, alumina, zinc oxide, tin oxide, zirconia,silica, or mixtures thereof. Optionally, the first protective film doesnot comprise a mixture of titania and alumina.

Clause 81: The coated article of clauses 79 or 80 wherein the secondprotective film comprises 35 to 65 weight percent titania; particularly45 to 55 weight percent titania; more particularly 50 weight percenttitania.

Clause 82: The coated article of any of the clauses 79 to 81 wherein thesecond protective film comprises 65 to 35 weight percent alumina,particularly 55 to 45 weight percent alumina, more particularly 50weight percent alumina.

Clause 83: The coated article of any of the clauses 79 to 82 furthercomprising a third protective film over at least a portion of the firstprotective film and positioned between the first protective film and thesecond protective film, or between the first protective film and thefunctional coating wherein the third protective film comprises titania,alumina, zinc oxide, tin oxide, zirconia, silica, or mixtures thereof.Optionally, the third protective film does not comprise a mixture oftitania and alumina.

Clause 84: The coated article of any of the clauses 66 to 83, whereinthe first transparent conductive oxide layer and/or the secondtransparent conductive oxide layer has a thickness of at most 400 nm,particularly at most 360 nm, more particularly at most 240 nm, moreparticularly at most 180 nm, more particularly at most 120 nm or moreparticularly at most 80 nm.

Clause 85: A coated article comprising a substrate, a functional layerover at least a portion of the substrate, a first protective film overat least a portion of the functional layer, and a second protective filmover at least a portion of the first protective film. The secondprotective film comprises titania and alumina, and is the outermostfilm.

Clause 86: The coated article of clause 85 wherein the first protectivefilm comprises titania, alumina, zinc oxide, tin oxide, zirconia, silicaor mixtures thereof.

Clause 87: The coated article of clauses 85 or 86 wherein the secondprotective film comprises 35 to 65 weight percent titania, particularly45 to 55 weight percent titania, more particularly 50 weight percenttitania.

Clause 88: The coated article of any of the clauses 85 to 87 wherein thesecond protective film comprises 65 to 35 weight percent silica,particularly 55 to 45 weight percent silica, more particularly 50 weightpercent silica.

Clause 89: The coated article of any of the clauses 85 to 88 wherein thefirst protective film comprises titania, alumina, zinc oxide, tin oxide,zirconia, silica or mixtures thereof. Optionally the first protectivefilm does not include a mixture of titania and alumina.

Clause 90: The coated article of any of the clauses 85 to 89 wherein thefunctional layer comprises a transparent conductive oxide layer that isselected from the group consisting of aluminum-doped zinc oxide,gallium-doped zinc oxide, and tin-doped indium oxide, particularlytin-doped indium oxide.

Clause 91: The coated article of any of the clauses of 85 to 90 whereinthe functional layer comprises a metal selected from the groupconsisting of silver, gold, palladium, copper or mixtures thereof,particularly silver.

Clause 92: The coated article of any of the clauses of 85 to 91 furthercomprising a third protective film over at least a portion of the firstprotective film and between the first protective film and the secondprotective film, or between the first protective film and the functionalcoating.

Clause 93: The coated article of any of the clauses 85 to 91 wherein thethird protective film comprises titania, alumina, zinc oxide, tin oxide,zirconia, silica or mixtures thereof. Optionally the third protectivefilm does not include a mixture of titania and alumina.

Clause 94: A method of protecting a functional layer comprisingproviding an article coated with a functional layer, applying a firstprotective film over at least a portion of the functional coating; andapplying a second protective film over at least a portion of the firstprotective film, wherein the second protective film comprises titaniaand alumina.

Clause 95: The method of clause 94 wherein the first protective filmcomprises titania, alumina, zinc oxide, tin oxide, zirconia, silica ormixtures thereof.

Clause 96: The method of clause 94 or 95 wherein the second protectivefilm comprises 35 to 65 weight percent titania, particularly 45 to 55weight percent titania, more particularly 50 weight percent titania.

Clause 97: The method of any of the clauses 94 to 99 wherein the secondprotective film comprises 65 to 35 weight percent silica, particularly55 to 45 weight percent silica, more particularly 50 weight percentsilica.

Clause 98: The method of any of the clauses 94 to 97 wherein the firstprotective film comprises titania, alumina, zinc oxide, tin oxide,zirconia, silica or mixtures thereof. Optionally the first protectivefilm does not include a mixture of titania and alumina.

Clause 99: The method of any of the clause 94 to 98 wherein thefunctional layer comprises a transparent conductive oxide layer that isselected from the group consisting of aluminum-doped zinc oxide,gallium-doped zinc oxide, and tin-doped indium oxide, particularlytin-doped indium oxide.

Clause 100: The method of any of the clauses of 94 to 99 wherein thefunctional layer comprises a metal selected from the group consisting ofsilver, gold, palladium, copper or mixtures thereof, particularlysilver.

Clause 101: The method of any of the clauses of 94 to 100 furthercomprising a third protective film over at least a portion of the firstprotective film and between the first protective film and the secondprotective film, or between the first protective film and the functionalcoating.

Clause 102: The method of any of the clauses 94 to 101 wherein the thirdprotective film comprises titania, alumina, zinc oxide, tin oxide,zirconia, silica or mixtures thereof. Optionally the third protectivefilm does not include a mixture of titania and alumina.

Clause 103: A method of reducing the absorption of a transparentconductive oxide layer, reducing emissivity of a coated article and/orreducing the absorbance of a coated article comprising providing asubstrate; applying a transparent conductive oxide layer, andheat-treating the coated article comprising the transparent conductiveoxide layer in an atmosphere that comprises between 0% and 1.0% oxygen,particularly between 0.% oxygen and 0.5% oxygen.

Clause 104: The method according to clause 103 wherein the transparentconductive oxide layer comprise indium-doped tin oxide (“ITO”) oraluminum-doped zinc oxide (“AZO”).

Clause 105: The method according to clauses 103 or 104 wherein thetransparent conductive oxide layer has a thickness of at least 125 nm,particularly at least 150 nm, more particularly at least 175 nm, and atmost 450 nm, at most 400 nm, at most 350 nm, at most 300 nm, at most 250nm or at most 250 nm.

Clause 106: The method according to any of the clauses of 103 to 105wherein the transparent conductive oxide layer comprises indium-dopedtin oxide (“ITO”), and wherein the atmosphere comprises between 0.75%and 1.25% oxygen.

Clause 107: The method according to any of the clauses 103 to 106wherein the transparent conductive oxide layer comprises a thickness ofat least 95 nm and at most 225 nm.

Clause 108: The method according to any of the clauses 103 to 107wherein the transparent conductive oxide layer comprises aluminum-dopedzinc oxide (“AZO”) and wherein the atmosphere comprises between 0% and0.5% oxygen, particularly between 0% and 0.25% oxygen, more particularlybetween 0% volume and 0.1% volume oxygen, or more particularly 0% volumeoxygen.

Clause 109: The method according to clause 108 wherein the transparentconductive oxide layer comprises a thickness of at least 225 nm and atmost 440 nm.

Clause 110: The method according to any of the clauses 103 to 109further comprising applying a functional coating over at least a portionof the substrate wherein the function coating is positioned between thesubstrate and the transparent conductive oxide layer.

Clause 111: The method according to any of the clauses 103 to 110further comprising applying a first protective film over at least aportion of the transparent conductive oxide layer, wherein the firstprotective film comprises titania, alumina, zinc oxide, tin oxide,zirconia, silica or mixtures thereof, and a second protective film overat least a portion of the first protective film wherein the secondprotective film comprises titania and alumina, wherein the secondprotective film is an outermost film.

Clause 112: A method of reducing a sheet resistance of a coated articlecomprising applying a coating to a substrate wherein the coatingcomprises a transparent conductive oxide layer at room temperature; andheating a top surface of the transparent conductive oxide layer to above380° F. or at least 435° F. for at least 5 second, at least 10 second,at least 30 seconds, and no more than 120 second, 90 second, 60 second,55 second, 50 seconds, 45 seconds, 40 second or 35 seconds.

Clause 113: The method according to clause 112 wherein the heating stepis flash annealing.

Clause 114: The method according to clause 112 or 113 wherein thetransparent conductive oxide layer is at least 125 nm and at most nm to950 nm.

Clause 115: The method according to any of the clauses 112 to 114wherein the transparent conductive oxide layer comprises tin-dopedindium oxide and is at least 105 nm and at most 171 nm, and wherein thesheet resistance of the coated article after the processing step is lessthan 20 ω/□.

Clause 116: The method according to any of the clauses 112 to 115,wherein the transparent conductive oxide layer comprises gallium-dopedzinc oxide having a thickness of at least 320 nm and at most 480 nm andwherein the sheet resistance of the coated article after the processingstep is less than 20 ω/□.

Clause 117: The method according to any of the clauses 112 to 116,wherein the transparent conductive oxide layer comprises alumina-dopedoxide having a thickness of at least 344 nm and at most 880 nm, andwherein the sheet resistance of the coated article after the processingstep is less than 20 ω/□.

Clause 118: The method according to any of the clauses 112 to 117,wherein the applying the coating step comprises a magnetron sputteredvacuum deposition process.

Clause 119: The method according to any of the clauses 112 to 118,wherein the applying the coating step does not use radiant heat.

Clause 120: The method according to any of the clauses 112 to 119further comprising applying a first protective film over at least aportion transparent conductive oxide layer, wherein the first protectivefilm comprise titania, alumina, zinc oxide, tin oxide, zirconia, silicaor mixtures thereof, and applying a second protective film over at leasta portion of the transparent conductive oxide layer wherein the secondprotective film comprises titania and alumina, and wherein the applyingthe first protective film and applying the second protective film occursbefore or after the processing step.

Clause 121: The method according to any of the clauses 112 to 120,wherein the heating step does not raise the top surface of thetransparent conductive oxide above 635° F.

Clause 122: The method according to any of the clauses 112 to 121,wherein the substrate is glass and the transparent conductive oxide hasan absorption not greater than 0.3.

Clause 123: The method according to any of the clauses 112 to 122,wherein the substrate is glass and the transparent conductive oxide hasan absorption at least as high as 0.05.

Clause 124: The method according to any of the clauses 112 to 123,wherein the coated article is a refrigerator door.

Clause 125: The method according to any of the clauses 112 to 124,wherein the applying step is done in an atmosphere that has an oxygencontent supplied to the atmosphere of between 0% and 1.5%.

Clause 126: The method according to any of the clauses 112 to 125,wherein the substrate is glass and the transparent conductive oxide hasan absorption not greater than 0.2 and at least as high as 0.05.

Clause 127: A method of making a coated article comprising applying atransparent conductive oxide layer over a substrate, raising a topsurface of the transparent conductive oxide to above 380° F., or atleast 435° F. and not raising the top surface of the transparentconductive oxide above 806° F. (or particularly 635° F.) for at least 5second, at least 10 second, at least 15 seconds, at least 20 seconds, atleast 25 seconds, at least 30 seconds, and no more than 120 second, 90second, 60 second, 55 second, 50 seconds, 45 seconds, 40 second or 35seconds.

Clause 128: The method according to clause 127 further comprising notheating the coated article above 635° F.

Clause 129: The method according to any of the clauses 127 to 128,wherein the transparent conductive oxide layer comprises tin-dopedindium oxide having a thickness of at least 96 nm and at most 171 nm anda sheet resistance of less than 25 ω/□.

Clause 130: The method according to any of the clauses 1127 to 129further comprising applying a protective layer over the transparentconductive oxide wherein the protective layer comprises titania andalumina.

Clause 131: A coated substrate having an a* between −9 and 1,particularly between −4 and 0, more particularly between −3 and 1, moreparticularly between −1.5 and −0.5; and a b* of between −9 and 1,particularly between −4 and 0, more particularly between −3 and 1, moreparticularly between −1.5 and −0.5 made by the method described in anyof the clauses 15 to 26.

Clause 132: A coated substrate having an a* between −9 and 1,particularly between −4 and 0, more particularly between −3 and 1, moreparticularly between −1.5 and −0.5; and a b* of between −9 and 1,particularly between −4 and 0, more particularly between −3 and 1, moreparticularly between −1.5 and −0.5 made by the method described in anyof the clauses 46 to 65.

Clause 133: A coated article made by the method described in any of theclauses 103 to 111.

Clause 134: A coated article made by the method described in any of theclauses 112 to 126.

Clause 135: A coated article made by the method described in any of theclauses 127 to 130.

Clause 136: Use of the underlayer of any of the clauses 1 to 14 or 27 to45 to provide an a* between −9 and 1, particularly between −4 and 0,more particularly between −3 and 1, more particularly between −1.5 and−0.5; and a b* of between −9 and 1, particularly between −4 and 0, moreparticularly between −3 and 1, or more particularly between −1.5 and−0.5.

Clause 137: Use of the first underlayer film and the second underlayerfilm of any of the clauses 15 to 26 or 46 to 65 to provide an a* between−9 and 1, particularly between −4 and 0, more particularly between −3and 1, more particularly between −1.5 and −0.5; and a b* of between −9and 1, particularly between −4 and 0, more particularly between −3 and1, or more particularly between −1.5 and −0.5.

Clause 138: Use of the embedded film of any of the clauses 27 to 65 todecrease sheet resistance.

Clause 139: Use of the protective layer of any of the clauses 85 to 93to increase durability of the coating on the substrate.

Clause 140: The coated article of any of the clauses 85 to 91 whereinthe protective layer has a thickness of at least at least 20 nm, 40 nm,60 nm, or 80 nm, 100 nm or 120 nm; and at most 275 nm, 255 nm, 240 nm,170 nm, 150 nm, 125 nm or 100 nm.

Clause 141: The coated article of any of the clauses 85 to 91 or 140wherein the first protective film can have a thickness of at least 10nm, at least 15 nm, at least 20 nm, at least 27 nm, at least 30 nm atleast 35 nm, at least 40 nm, at least 54 nm, at least 72 nm; and at most85 nm, 70 nm, 60 nm, 50 nm, 45 nm, or 30 nm.

Clause 142: The coated article of any of the clauses 85 to 91, 140 or141 wherein the second protective film can have a thickness of at least10 nm, at least 15 nm, at least 20 nm, at least 27 nm, at least 35 nm,at least 40 nm, at least 54 nm, at least 72 nm; and at most 85 nm, 70nm, 60 nm, 50 nm, 40 nm 45 nm, 30 nm.

Clause 143: The coated article of any of the clauses 85 to 91, or 140 to142 wherein the optional third protective film can have a thickness ofat least 5 nm, at least 10 nm, at least 15 nm at least 27 nm, at least35 nm, at least 40 nm, at least 54 nm, at least 72 nm; and at most 85nm, 70 nm, 60 nm 50 nm, 45 nm, 30 nm or at most 30.

The invention claimed is:
 1. A coated article comprising a substrate, anunderlayer over at least a portion of the substrate, the underlayercomprising a first underlayer film wherein the first underlayer filmcomprises a first refractive index material, wherein the firstunderlayer film is in direct contact with the substrate and wherein thefirst refractive index material comprises zinc, and a second underlayerfilm over at least a portion of the first underlayer film wherein thesecond underlayer film comprises a second refractive index material, andwherein the first refractive index material has a refractive indexgreater than the second refractive index material, a transparentconductive oxide layer over at least a portion of the underlayer and anembedded film embedded within the transparent conductive oxide layerwherein the embedded film comprises a third refractive index material,and wherein the third refractive index material has a refractive indexgreater than the second refractive index material.
 2. The coated articleaccording to claim 1, wherein the third refractive index materialcomprises tin oxide and zinc oxide.
 3. The coated article according toclaim 1, wherein the embedded film has a thickness in the range of 15 nmto 30 nm.
 4. The coated article according to claim 1, wherein thetransparent conductive oxide layer comprises tin-doped indium oxide. 5.The coated article according to claim 1, wherein the embedded film ispositioned closer to a bottom of the transparent conductive oxide layer.6. The coated article according to claim 1, wherein the embedded film ispositioned closer to a top of the transparent conductive oxide layer. 7.The coated article according to claim 1, wherein the embedded film ispositioned at approximately a middle of the transparent conductive oxidelayer.
 8. The coated article according to claim 1, further comprising aprotective layer over at least a portion of the transparent conductiveoxide layer, wherein the protective layer comprises a first protectivefilm comprising titania, alumina, zinc oxide, tin oxide, zirconia,silica alloys thereof or mixtures thereof; and a second protective filmover at least a portion of the first protective film, wherein the secondprotective film comprises a mixture of titania and alumina.
 9. A coatedarticle comprising a substrate; an underlayer over at least a portion ofthe substrate, wherein the underlayer comprises a first underlayer filmand a second underlayer film over at least a portion of the firstunderlayer film, wherein the first underlayer film comprises a firstrefractive index material that comprises zinc, wherein said secondunderlayer film comprises a second refractive index material, whereinthe first refractive index material is in direct contact with thesubstrate and has a refractive index greater than the second refractiveindex material; a first transparent conductive oxide layer over at leasta portion of the underlayer, an embedded film over at least a portion ofthe first transparent conductive oxide layer, wherein the embedded filmcomprises a third refractive index material, and wherein the thirdrefractive index material has a refractive index greater than the secondrefractive index material; and a second transparent conductive oxidelayer over at least a portion of the embedded film.
 10. The coatedarticle according to claim 9, wherein the embedded film comprises tinoxide and zinc oxide.
 11. The coated article according to claim 9,wherein the first transparent conductive oxide layer and the secondtransparent conductive oxide layer comprise tin-doped indium oxide(“ITO”).
 12. The coated article according to claim 9, wherein theembedded film has a thickness of at least 15 nm and at most 30 nm. 13.The coated article according to claim 9, wherein the first transparentconductive oxide layer is thicker than the second transparent conductiveoxide layer.
 14. The coated article according to claim 9, furthercomprising a protective layer over at least a portion of the secondtransparent conductive oxide layer, wherein the protective layercomprises a first protective film comprising titania, alumina, zincoxide, tin oxide, zirconia, silica or mixtures thereof; and a secondprotective film over at least a portion of the first protective film,wherein the second protective film comprises a mixture of titania andalumina.
 15. A method of reducing the sheet resistance of a coatedarticle comprising (a) applying a first underlayer film over at least aportion of a substrate, wherein the first underlayer film comprises afirst refractive index material, wherein the first underlayer film is indirect contact with the substrate and wherein the first refractive indexmaterial comprise zinc; (b) applying a second underlayer film over atleast a portion of the first underlayer film, wherein the secondunderlayer film comprises a second refractive index material; (c)applying a first transparent conductive oxide layer over at least aportion of the second underlayer film; (d) applying an embedded filmover at least a portion of the first transparent conductive oxide layer,wherein the embedded film comprises a third refractive index material,and wherein the third refractive index material has a refractive indexgreater than the second refractive index material; and (e) applying asecond transparent conductive oxide layer over at least a portion of theembedded film.
 16. The method according to claim 15, wherein the thirdrefractive index material comprises tin oxide and zinc oxide.
 17. Themethod according to claim 15, wherein the first transparent conductiveoxide layer comprises tin-doped indium oxide.
 18. The method accordingto claim 15, wherein the embedded film is applied at a thickness of atleast 15 nm, and at most 30 nm.
 19. The method according to claim 15,wherein the first transparent conductive oxide layer is thicker than thesecond transparent conductive oxide layer.
 20. The method according toclaim 15 further comprising applying a first protective film over atleast a portion of the second transparent conductive oxide layer, andapplying a second protective film over at least a portion of the firstprotective film, wherein the second protective film comprises a mixtureof titania and alumina, and wherein the first protective film comprisestitania, alumina, zinc oxide, tin oxide, zirconia, silica or mixturesthereof.